CA2164949C

CA2164949C - Photochromic naphthopyran compounds

Info

Publication number: CA2164949C
Application number: CA002164949A
Authority: CA
Inventors: David B. Knowles
Original assignee: Transitions Optical Inc
Current assignee: Transitions Optical Inc
Priority date: 1993-06-21
Filing date: 1994-06-13
Publication date: 1999-06-15
Anticipated expiration: 2014-06-13
Also published as: AU672126B2; WO1995000866A1; CA2164949A1; EP0704067B1; KR960703238A; US5458815A; JPH08512031A; CN1053445C; AU7173294A; US5384077A; DE69427859D1; BR9407267A; EP0704067A4; CN1125985A; JP2839716B2; EP0704067A1; KR100267063B1; SG50593A1; DE69427859T2

Abstract

Described are novel reversible photochromic naphthopyran compounds, examples of which are compounds substituted at the 3 position of the pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl substituent. Also described are organic host materials that contain or that are coated with such compounds.
Articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., spiro(indoline) type compounds, are also described.

Description

216~4~
~vo 95/OWK~ PCTrUS94/06725 PHOTOCHROMIC NAPHTHOPYRAN COMPOUNDS

DESCRIPTION OF THE l~V~:r~lloN
5The present invention relates to certain novel naphthopyran compound6. More particularly, this invention relate6 to novel photochromic naphthopyran c. o~ds and to compositions and articles containing such novel naphthopyran c;. ,ound6. When exposed to light radiation involving ultraviolet rays, such as the ultraviolet 10 radiation in sunlight or the light of a mercury lamp, many photochromic c. ~o~nds exhibit a reversible change in color. When the ultraviolet radiation is discontinued, such a photochromic compound will return to its original color or colorless state.
Various classes of photochromic c~ .~G~-ds have been 15 synthesized and suggested for use in applications in which a sunlight-induced reversible color change or darkening is desired.
U.S. Patent 3,567,605 (Becker) describes a series of pyran derivatives, including certain benzopyrans and naphthop~ ~ns. These cc pounds are described as derivatives of chromene and are reported 20 to undergo a color change, e.g., from colorless to yellow-orange, on irradiation by ultraviolet light at temperatures below about -30~C.
Irradiation of the c. po~-ds with visible light or upon raising the temperature to above about 0~C is reported to reverse the coloration to a colorless state.
The present invention relates to novel naphthopyran compounds whose colored forms have been found to have an unexpectedly higher absorption maxima than correspo~d~ng compounds having no substituents or different substituents at the same ring position. These c- ~ounds are substituted at the 3 position of the 30 pyran ring with (i) an aryl substituent and (ii) a phenyl substituent having a 5- or 6 e~ heterocyclic ring fused at the number 3 and 4 carbon atoms of the phenyl substituent.

W 0 95/O~K~ 9 PCTrUS94/06725 DETATTFn DESCRIPTION OF T~F T~vENTIoN
In recent years, photochromic plastic materials, particulsrly plastic materials for optical applications, have been the subject of considerable attention. In particular, photochromic 5 ophthalmic plastic lenses have been investigated because of the weight advantage they offer, vis-a-vis, glass lenses. Moreover, photochromic transparencies for vehicles, such as cars and airplanes, have been of interest because of the potential safety feature6 that such transparencies offer.
Photochromic compounds useful in optical applications, such as conventional ophthalmic lenses, are those which posse6s (a) a high quantum efficiency for coloring in the near ultraviolet, (b) a low quantum yield for bleaching with white light, and (c) a relatively fast thermal fade at ambient temperature but not 80 rapid 15 a thermal fade rate that the combination of white light ble~ch~ng and thermal fade prevent coloring by the ultraviolet component of strong sunlight. In addition, the aforesaid properties are desirably retained in conventional rigid synthetic plastic materials customarily used for ophthalmic and plano lenses when such materials 20 have applied to or incorporated therein such photochromic cc pounds.
Compounds, such as 3,3-diphenyl-3H-naphtho[2,1-b]pyran, change color on exposure to the near ultraviolet; but, at room temperature and above, this c~ ~o~ld bleaches too rapidly for use in an ophthalmic lens. Substitution of either or both of the phenyl 25 rings at the meta or para positions result in an even more rapid bleach rate, and therefore an even lower color intensity. The c~ ~o~.d, 2,2-diphenyl-2H-naphtho[1,2-b]pyran, al60 colors on exposure to near ultraviolet light at room temperature but does not bleach in a reasonable period of time. Substitution of either or 30 both of the phenyl rings at the meta or para positions have little effect on the rate of bleaching of these compounds.
In accordance with the present invention, it has now been discovered that certain novel naphthopyran c~ ~,o~,ds having a high quantum efficiency for coloring in the near ultraviolet and an ~ J PCTAUS94/06725 acceptable rate of fade may be prepared. The6e cl ~lou~ds may be described as naphthopyran6 6ubstituted at the 3 po6ition of the pyran ring with (i) an aryl sub6tituent and (ii) a phenyl substituent having a 5- or 6-member heterocyclic ring fused at the 5 number 3 and 4 carbon atoms of the phenyl 6ubstituent and may be represented by the following graphic formula:

~R~

(R2)b In graphic formula I, Rl and R2 may each be Cl-C10 alkyl, 20 C5-C7 cycloalkyl, e.g., cyclopentyl, cyclohexyl, and cycloheptyl, halogen, R(R')N-, or the group, -0-L, wherein R and R' are each hydrogen or Cl-C3 alkyl, L is a Cl-C12 alkyl, e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl, phenyl(Cl-C3)alkyl, e.g., benzyl, phenethyl, 25 phenylpropyl, mono-, di- and tri(Cl-C3) alkylphenyl, e.g., tolyl, xylyl, mesityl, and cumenyl, Cl-C5 alkylcarbonyl, and halo(Cl-C4)alkylcarbonyl, which includes mono-, di-, or trl-halo substituents, Cl-C4 monoalkylaminocarbonyl, acetonyl, pyridyl, substituted or unsubstituted arylcarbonyl, said aryl group being 30 phenyl or naphthyl, said aryl substituents being Cl-C4 alkyl, Cl-C4 alkoxy, e.g., methoxy, ethoxy, propoxy, and butoxy, halogen, C5-C7 cycloalkyl, or Cl-C4 alkyl substituted C5-C7 cycloalkyl, said halogen (or halo) groups described above being chloro, fluoro, or bromo, and a and b are each the integer6 0, 1 or 2 provided that the 35 6um of a and b i6 not more than 2.

W O 95/00866 PCT~US94/06725 2 1 ~

Preferably, Rl and R2 are each R(R')N-, or the group, -0-L, wherein R and R' are each hydrogen or Cl-C2 alkyl, L is Cl-C4 alkyl, Cl-Cz alkylphenyl, phenyl(Cl-C2)alkyl, Cl-C2 alkylcarbonyl, halo(Cl-C2)alkylcarbonyl, or Cl-C2 monoalkylaminocarbonyl, said halo 5 group being chloro or fluoro, and a and b are each the integer 0 or 1.
B may be the sub6tituted or unsubstituted aryl group, naphthyl or phenyl, said aryl substituents being Cl-C5 alkyl, halo(Cl-C5)alkyl, hydroxy, Cl-C5 alkoxy, Cl-C4 alkoxy(Cl-C4)alkyl, 10 halogen, or R(R')N-, wherein R and R' are each hydrogen or Cl-C3 alkyl, said halogen (or halo) groups being fluorine, chlorine, or bromine. Preferably, 8 is represented by the following graphic formula II:

~ ( R7 ) d I I

In graphic formula II, R6 is hydrogen, Cl-C4 alkyl, Cl-C4 25 alkoxy, fluoro, or chloro and each R7 is a Cl-C4 alkyl, Cl-C4 alkoxy, hydroxy, chloro, or fluoro and d is an integer from 0 to 2.

OWK~ ~ ~ fi l 9 4 9 PCT~US94/06725 B' may be represented by one of the following graphic formulae III or IV:

10 ~X ~xX~-(R3)c tR3)C

III I V

In graphic formula III and IV, X i6 oxygen or nitrogen and Y is carbon or oxygen, provided that when X iB nitrogen, Y is carbon; R4 and R5 are each hydrogen or Cl-C5 alkyl; each R3 is a Cl-C5 alkyl, Cl-C5 alkoxy, hydroxy, or halogen, said halogen 20 substituent being chloro, fluoro, or bromo, and c is an integer from 0 to 3, e.g., 0, 1, 2, or 3. Preferably, B' is represented by graphic formula III, wherein X i8 oxygen; Y is carbon or oxygen; R4 and R5 are each hydrogen or Cl-C4 alkyl; each R3 is a Cl-C4 alkyl, Cl-C4 alkoxy, hydroxy, or fluoro; and c is the integer 0, 1, or 2.
In graphic formula III, when X is oxygen and Y is carbon and c is zero, the group is a 2,3-dihydrobenzofuran-5-yl; when X is oxygen and Y is oxygen and c is zero, the group is 1,3-benzo-dioxole-5-yl; and when X is nitrogen and Y is carbon and c is zero, the group is indoline-5-yl. In graphic formula IV, when X is oxygen 30 and Y is carbon, the unsubstituted group is a chL. ~- 6-yl; when X
i6 oxygen and Y i8 oxygen, the unsubstituted group is a 1,4-benzodioxan-6-yl; and when X is nitrogen and Y is carbon, the unsubstituted group is 1,2,3,4-tetrahydroquinoline-6-yl.
For brevity, these group6 will be referred to herein as fused 35 heterocyclic-phenyl groups.

W O 95/O~K~ PCTrUS94/06725 9 4 ~ 6 -Cc ,o~nds represented by graphic formula I are prepared by Friedel-Crafts methots usin~ an appropriately substituted or unsubstituted benzoyl chloride of graphic formula V with a commercially available fused heterocyclic-benzene compound to 5 produce B' structures of graphic formula III or IV. See the publication Friedel-Crafts An~ RelAted ~ tinnR, George A. Olah, Interscience Publishers, 1964, Vol. 3, Chapter XXXI (Aromatic Ketone Synthesi6), and "Regioselective Friedel-Crafts Acylation of 1,2,3,4-Tetrahydroquinoline and Related Nitrogen Heterocycles:
10 Effect on NH Protective Groups and Ring Size" by Ishihara, Yugi et al, J. Chem. Soc., Perkin Trans. 1, pages 3401 to 3406, 1992. If a fused heterocyclic-benzene compound cont~n~ng an oxygen is not commercially available, it may be prepared from an appropriately substituted phenol as described in OrgAnic ~ActinnR, Vol. II, page6 15 26 and 27.
In reaction A shown below, the ~ -~-ds represented by graphic formulae V and III sre dissolved in a solvent, such as carbon disulfide or methylene chloride, in the presence of a Lewis acid, such as aluminum chloride, to form the corresponding 20 heterocyclic fused benzophenone represented by graphic formula VII.

'~0 95/00866 ~16 4 9 4 9 PCT~US94106725 R~5 o T~ 11 10 ~\Cl I ~X'-l~Cll.~ ~X", (R7)d (R3)c tR7)d (R3)C

V III VII

REACTION A
In reaction B shown below, the heterocyclic fused 20 benzophenone represented by graphic formula VII is reacted with sodium acetylide in a suitable solvent, such as dry tetrahydrofuran, to form the corresponding propargyl alcohol represented by graphic formula VIII.

W O 95/00866 PCTrUS94/06725 2~6~g49 P~ 11 Rf ~ c_ CH
10 ~/~CYX"~-CIls8r~ ~x~

~R7)d ~R~)C ~R7)d tR3)0 VII VIII

REACTION B

In reaction C shown below, the propargyl alcohol repregented by graphic formula VIII i8 coupled with the appropriately substituted 2-naphthol, represented by graphic formula IX, under acidic conditions to form the naphthop~Lo~s of graphic formula X, which are c ,,ounds represented by graphic formula I.

~VO 95/00866 ~ S PCTAUS94/06725 O C--CH
~/ H

(R7)d (R3)c (R~ (R2)b V
VIII (Rl)o IX

~YX, X (R3)C

REACTION C

By 6ubstituting the fused heterocyclic-phenyl group of graphic 25 formula IV for that of graphic formula III in reaction A, compound6 similar to those represented by graphic formula X except for a 6-member heterocyclic ring fused at the number 3 and 4 carbon atoms of the 3-phenyl substituent may be prepared.
Cc ~o~nds represented by graphic formula I may be used in 30 tho~e applications in which organic photochromic substances may be employed, such as optical lenses, e.g., ophthalmic and plano lenses, face shields, goggles, visors, camera lenses, windows, automotive windshields, aircraft and automotive transparencies, e.g., T-roofs, sidelight6, and backlights, plastic films and sheets, textiles and 35 coatings, e.g., coating compositions such as paints, and W O 951OWK~ PCTrUS94/06725 verification marks on security documents, e.g., documents such as banknotes, passports and drivers' licenses for which authentication or verification of authenticity may be desired. Naphtho~ ns represented by graphic formula I exhibit color changes from 5 colorless to colors ranging from yellow to orange.
Examples of contemplated naphthopyrans within the scope of the invention are the following:
(1) 3-(2,3-dihydrobenzofuran-5-yl)-3-phenyl-3H-naphtho-[2,1-b~pyrsn;
10 (2) 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;

(3) 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-methoxyphenyl)-3H-naphtho[2,1-b]pyran;

(4) 5-acetoxy-3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;

(5) 8-methoxy-3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;

(6) 3-(4-methoxyphenyl)-3-(2,4,7-trimethyl-2,3-dihydro-benzofuran-5-yl)-3H-naphtho[2,1-b]pyran;
20 (7) 3-(2-methyldihydrobenzofuran-5-yl)-3-(2-fluoro-phenyl)-3H-naphtho[2,1-b]pyran;
(8) 3-(1,4-benzodioxan-6-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;
(9) 3-(1,3-benzodioxole-5-yl)-3-phenyl-3H-naphtho-[2,1-b]pyran;
(10) 3-(indoline-5-yl)-3-phenyl-3H-naphtho[2,1-b]pyran; and (11) 3-(1,2,3,4-tetrahydroquinoline-6-yl)-3-phenyl-3H-naphtho[2,1-b]pyran.

Commercially available photoreactive inorganic gla66 len6e6 cont~ining 6ilver halide particle6 darken to a neutral gray or brown color in sunlight. In order to duplicate this color change in a plastic lens using the organic photochromic naphthopyrans of graphic formula I, it is contemplated that such naphthopyrans be uged in ~VogS/~WK~ ~ ~ Q PCTnJS94l0672S

combination with other appropriate complementary organic photochromic materials 60 that together they produce the desired gray or brown color shade when the plastic lens cont~n~g such photochromic materials is exposed to ultraviolet light. For 5 example, a c po~ld which colors to yellow may be blended with a compound that colors to an appropriate purple to produce a brown shade. Similarly, a compound which is orange in its colored state will produce a ~hade of gray when used in con~unction with an appropriate blue coloring compound.
Particularly contemplated classe6 of complementary organic photochromic c 3unds that may be used include: the purple/blue spiro(indoline) benzoxazine~ described in U.S. Patent 4,816,584;
~piro(indoline) pyridobenzoxazine photochromic compound6 described in U.S. Patent 4,637,698; spiro(indoline) naphthoxazines described 15 in U.S. Patents 3,562,172, 3,578,602, 4,215,010 and 4,342,668; and benzopyrans and naphthopyrans having a nitrogen-contA1n~ng 6ubstituent in the 2-position of the pyran ring, a6 described in U.S. Patent 4,818,096. All of the aforede6cribed oxazine- and pyran-type organic photochromic compounds are reported to exhibit a 20 color change of from colorles~ to purple/blue on exposure to ultraviolet light.

Other contemplated complementary organic photochromic compounts that are reported to exhibit a color change of from 25 colorless to yellow/orange when exposed to W light that may be used in combination to ~t.~ --t the yellow/orange color of the naphthopyran c po~-ds of the present invention lnclude: benzopyrans and naphthopyrans having a spiro adamantane group in the 2-position of the pyran ring, as described in U.S. Patent 4,8Z6,977; and 30 naphthopyran compounds described in U.S. Patent 5,066,818.
The naphthopyran compounds of the present invention may be used in admixture with or in conjunction with the aforedescribed complementary or augmenting organic photochromic compounds in amounts and in a ratio such that an organic host material to which W O 95/OWK~ PCTAUS94/06725 2~6~

the mixture of compound6 is applied or in which they are incorporated exhibits a substantially neutral color when activated with unfiltered ~nlight, i.e., as near a neutral gray or brown color as possible given the colors of the activated photochromic 5 compounds. The relative amounts of the photochromic c. ~ounds used will vary and depend in part upon the relative intensities of the color of the activated species of such compounts.
For example, the naphthopyran compounds of the present invention may be combined with one or more of the aforede6cribed 10 purple/blue oxazine- and/or pyran-type organic photochromic compounds in amounts and in a ratio such that an organic host material to which the mixture of compound6 is applied or in which they are incorporated exhibits a near-brown color. Generally, the weight ratio of the aforedescribed oxazine- and pyran-type 15 compound(s) to the naphthopyran c~ "o~d(s) of the present invention will vary from about 1:3 to about 3:1, e.g., between about 1:2 or 0.75:1 and about 2:1.
A near neutral gray color exhibits a spectrum that has relatively equal absorption in the visible range between 400 and 700 20 nanometers, e.g., between 440 and 660 nanometers. A near neutral brown color exhibits a spectrum in which the absorption in the 400-550 nanometer range is moderately larger than in the 550-700 nanometer range. An alternative way of describing color is in terms of its chromaticity coordinates, which describe the qualities of a 25 color in addition to its luminance factor, i.e., its chromaticity.
In the CIE system, the chromaticity coordinates are obtained by taking the ratios of the tristimulus values to their sum, e.g., x=X/X+Y+Z and y=Y/X+Y+Z. Color as described in the CIE system can be plotted on a chromaticity diagram, usually a plot of the 30 chromaticity coordinates x and y. See pages 47-52 of Principles Qf Color Te~hnolo~y, by F. W. Billmeyer, Jr. and Max Saltzman, Second ~dition, John Wiley and Sons, N.Y. (1981).
The amount of photochromic substance or composition-containing same applied to or incorporated into a host material is 35 not critical provided that a sufficient amount is used to produce a vogs/00866 2~6~9~9 PCTrUS94/06725 photochromic effect discernible to the naked eye. Generally such amount can be described as a photochromic amount. The particular amount used depends often upon the intensity of color desired upon irradiation thereof and upon the method used to incorporate or apply 5 the photochromic substances. Typically, the more compound applied or incorporated, the greater is the color intensity.
Generally, the amount of each photochromic substance incorporated into or applied to the host material may range from about 0.01 or 0.05 to about 10 to 20 percent by weight. More 10 typically, the amount of photochromic substance(s) incorporated into or applied to the host material will range from about 0.01 to about 2 weight percent, more particularly, from about 0.01 to about 1 weight percent, e.g., from about 0.1 or 0.5 to about 1 weight percent, based on the weight of the host material. Expressed 15 differently, the total amount of photochromic substance incorporated into or applied to an optical host material may range from about 0.15 to about 0.35 milligrams per square centimeter of surface to which the photochromic 6ub6tance(6) is incorporated or applied.
Photochromic c. ,,ounds of the present invention, mixtures 20 of such compounds with other photochromic compounds, or compositions containing same (hereinafter "photochromic substances") may be applied to or incorporated into a host material by various methods described in the art. Such methods include dissolving or dispersing the substance within the host material, e.g., imbibition of the 25 photochromic substance into the host material by immersion of the host material in a hot solution of the photochromic substance or by thermal transfer; providing the photochromic substance as a separate layer between adjacent layers of the host material, e.g., as a part of a polymer film; and applying the photochromic substance as part 30 of a coating placed on the surface of the host material. The term "imbibition" or "imbibe" is intended to mean and include permeation of the photochromic substance alone into the host material, solvent assisted transfer absorption of the photochromic substance into a porous polymer, vapor phase transfer, and other such transfer 35 mechanisms. See U.S. Patent No. 5,066,818 column 14, line 41 to column 15, line 25 for examples of the above methods.

W O 95/~K~ PCT~US94/06725 ~4g~5 The polymer ho6t material will usually be transparent, but may be translucent or even opaque. The polymer protuct need only be transparent to that portion of the electromagnetic spectrum, which sctivates the photochromic substance, i.e., that wavelength of 5 ultraviolet ( W ) light that produces the open form of the substance and that portion of the visible spectrum that includes the absorption maximum wavelength of the substance in its W activated form, i.e., the open form. Further, the resin color should not be such that it ma6ks the color of the activated form of the 10 photochromic substance, i.e., 80 the change in color is readily apparent to the observer. Preferably, the host material article is a solid transparent or optically clear material.
Examples of host materials which may be used with the photochromic substances or compositions described herein include:
15 polymers, i.e., homopolymers and copolymers, of polyol(allyl carbonate) rs, e.g., diethylene glycol bis(allyl carbonate), polymers, i.e., homopolymers and copolymers, of polyfunctional acrylate monomers, polyacrylates, which are polymers of esters of acrylic acid or methacrylic acid, such as methyl acrylate and methyl 20 methacrylate, cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), polyurethanes, polycarbonates, poly(ethylene terephthalate), polystyrene, copoly(styrene-methyl methacrylate) 25 copoly(styrene-acrylonitrile), polyvinylbutyral and polymers, i.e., homopolymers and copolymers, of diallylidene pentaerythritol, particularly copolymers with polyol (allyl carbonate) - ~ ?rs, e.g., diethylene glycol bis(allyl carbonate), and acrylate ~rs.
Transparent copolymers and blends of the transparent 30 polymers are also suitable as host materials. Preferably, the host material is an optically clear polymerized organic material prepared from a polycarbonate resin, such as the carbonate-linked resin derived from bisphenol A and phosgene, i.e., poly(4,4'-dioxy-diphenol-2,2-propane), which is sold under the trademark, LEXAN; a ~ ~. 6 ~ ~ 4 9 PCT/US94/06725 poly(methyl methacrylate), 6uch as the material sold under the trademark, PLEXIGLAS; polymerizates of a polyol(allyl carbonate), e6pecially diethylene glycol bis(allyl carbonate), which monomer is 601d under the trademark, CR-39, and polymerizates of copolymers of 5 a polyol (allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), with other copolymerizable ~ ric materials, such as copolymers with vinyl acetate, e.g., copolymers of from 80-90 percent diethylene glycol bis(allyl carbonate) and 10-20 percent vinyl acetate, particularly 80-85 percent of the bis(allyl 10 carbonate) and 15-20 percent vinyl acetate, and copolymers with a polyurethane having terminal diacrylate functionality, a6 described in U.S. Patent 4,360,653, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, polystyrene and copolymer6 of styrene with methyl methacrylate, vinyl acetate and 15 acrylonitrile.
Polyol (allyl carbonate) ~.c -rs which may be polymerized to form a transparent host material are the allyl carbonates of linear or branched aliphatic or aromatic liquid polyols, e.g., aliphatic glycol bis(allyl carbonate) c~ po~nds, or alkylidene 20 bisphenol bis(allyl carbonate) cc r,ow,t6. These monomers can be described as unsaturated polycarbonates of polyol6, e.g, glycols.
The monomers can be prepared by procedures well known in the art, e.g., U.S. Patents 2,370,567 and 2,403,113.
Compatible (chemically and color-wise) tints, i.e., dyes, 25 may be applied to the host material to achieve a more aesthetic result, for medical reasons, or for reasons of fashlon. The particular dye selected will vary and depend on the aforesaid need and result to be achieved. In one embodiment, the dye may be selected to complement the color resulting from the activated 30 photochromic substances, e.g., to achieve a more neutral color or absorb a particular wavelength of incident light. In another embodiment, the dye may be selected to provide a desired hue to the host matrix when the photochromic substance is in an inactivated ~tate.

~4~9 16 -Typically, tinting is accomplished by immersion of the host material in a heated aqueous dispersion of the selected dye. The degree of tint is controlled by the temperature of the dye bath and the length of time the host material i8 allowed to remain in the 5 bath. Generally, the dye bath is at temperatures of less than 100~C, e.g., from 70~C to 90~C, such as 80~C, and the host material ~ -ins in the bath for less than five (5) minutes, e.g., between about 0.5 and 3 minutes, e.g., about 2 minutes. The degree of tint i8 ~uch that the resulting article exhibits from about 70 to 85 10 percent, e.g., 80-82 percent, light transmission.
Adjuvant materials may also be incorporated into the host material with the photochromic substances prior to, simultaneously with or subsequent to application or incorporation of the photochromic substances in the host material. For example, 15 ultraviolet light absorber~ may be admixed with photochromic substances before their application to the host material or such absorbers may be superposed, e.g., superimposed, as a layer between the photochromic substance and the incident light. Further, stabilizer6 may be admixed with the photochromic substances prior to 20 their application to the host material to improve the light fatigue resistance of the photochromic substances. Stabilizers, such as hindered amine light stabilizers and singlet oxygen quenchers, e.g., a nickel ion complex with an organic ligand, are contemplated. They may be used alone or in combination. Such stabilizers are described 25 in U.S. Patent 4,720,356. Finally, appropriate protective coating(s) may be applied to the surface of the host material.
These may be abrasion resistant coatings and/or coatings that serve as oxygen barriers. Such coatings are known in the art.
The present invention is more particularly described in the 30 following examples which are intended a~ illu~trative only, since numerous modifications and variations therein will be apparent to those skilled in the art.

'~0 9S/~WK~ 3 ~ ~ 4 ~ PCTAUS94106725 Step 1 2,3-dihydrobenzofuran (9.25 grams, 0.077 moles) was added to a reaction flask cont~ining 100 milliliters of methylene chloride 5 and 10.8 grams (0.077 moles) of benzoyl chloride. Aluminum chloride (12.32 grams, 0.092 moles) was added slowly and the resulting mixture was stirred for 2 hour6 under a nitrogen atmosphere. The reaction mixture was added to a 5 percent aqueous hydrochloric acid solution and stirred until colorless. The organic layer was 10 separated and the aqueous layer was back extracted with 100 milliliters of methylene chloride. The organic portions were combined and added to a 10 percent aqueous sodium hydroxide solution containing 1 milliliter of triethylamine to remove any unreacted starting material. The mixture was stirred and the organic layer 15 was separated and dried over magnesium sulfate. The residual methylene chloride was removed under vacuum. The resulting pale yellow oil was induced to crystallize by dissolving it in hexane and then cooling the solution in a dry ice/acetone bath. 7.8 grams of the crystalline product, 5-benzoyl-2,3-dihydrobenzofuran, was 20 collected by vacuum filtration.

Stey 2 5-benzoyl-2,3-dihydrobenzofuran (7.8 grams, 0.035 mole) from Step 1 was added to a reaction flask cont~n~ng 300 milliliters 25 of tetrahydrofuran saturated with acetylene. 10.0 grams of a 18 weight percent suspension of sodium acetylide in xylene/mineral oil (0.035 moles of sodium acetylide) was added slowly to the stirred solution. After 16 hours at room temperature and under a nitrogen atmosphere, the reaction mixture was dissolved in 5 percent aqueous 30 hydrochloric acid solution. The resulting mixture was extracted with three 100 milliliter portions of methylene chloride. The organic extracts were combined and dried over magnesium sulfate.
The solvent, methylene chloride, was removed under vacuum to yield 7.0 grams of the product cont~ining 1-(2,3-dihydrobenzofuran-5-yl)-35 1-phenyl-2-propyn-1-ol which was not purified further but u8ed directly in the next step.

WO 95/O~K~ PCT~US94/06725 4 ~ 18 -Step 3 The product (7.0 grams) from Step 2 was added to a reaction flask containing 300 milliliter6 of benzene and 4.0 grams of 5 2-hydroxynaphthalene. A catalytic amount of dodecylbenzene6ulfonic acid (3 drop6) wa6 added. The mixture was heated to 40~C and stirred for 1 hour under a nitrogen atmosphere. Afterwards, the reaction mixture was dis601ved in distilled water and washed with about 300 milliliters of 10 percent aqueous sodium hydroxide. The 10 organic layer was separated, dried over magnesium sulfate and the remaining benzene wa6 removed under vacuum. The resulting residue was induced to crystallize by dissolving it in a hexane/ether mixture and cooling the mixture in a dry ice/acetone bath. The resulting crystals were collected by vacuum filtration, dis601ved in 15 a 9:1 mixture of hexane:ethyl acetate, stirred for one half hour, and collected by vacuum filtration. The crystalline product, about 3.0 ~ram6, melted at 128-131~C and was 97.7% pure as determined by liquid chromatographic analysis. A nuclear magnetic resonance (NMR) spectrum showed the solid crystalline product to have a structure 20 consi6tent with 3-(2,3-dihydrobenzofuran-5-yl)-3-phenyl-3H-naphtho-[2,1-b]pyran.

~.'XAI~lPT.F: 2 The procedure of Step 1 of Example 1 was utilized except 25 for the following: 2-fluorobenzoyl chloride (13.2 grsms, 0.083 mole) wa6 used instead of benzoyl chloride; the mixture was stirred for one hour; and the combined organic fraction was back extracted with distilled water. 19.5 grams of product cont~n~ng 5-(2-fluoro-benzoyl-2,3-dihydrobenzofuran was recovered.
The procedure of Step 2 of Example 1 was utilized except that 5-(2-fluorobenzoyl)-2,3-dihydrobenzofuran (8 grams, 0.033 moles) was used as the reactant; the reaction mixture was stirred 20 hours; 10% aqueous hydrochloric acid was used to dissolve the reaction mixture; and the combined organic fraction was washed with vo gs/~wK6 ~ 16 4 9 ~- ~ PCTrUS94/06725 two portions of water, about 300 milliliters each. The yield of product cont~;n;ng l-(Z,3-dihydrobenzofuran-5-yl)-1-(2-fluoro-phenyl)-2-propyn-1-ol was 7.0 grams.
The procedure of Step 3 of Example 1 was utilized except 5 that 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-fluorophenyl)-2-propyn-1-ol (7.0 gram~), toluene (300 milliliters), and a catalytic amount of p-toluene6ulfonic acid (3 drops) were used; and the reaction mixture was heated to 45~C. After the organic layer was separated, the aqueous layer was washed once with about 100 milliliters of 10 methylene chloride and the organic fraction~ were combined. The combined organic extracts were dried over magnesium sulfate and reduced under vacuum to yield 7.0 grams of oil.
The oil was purified using a silica gel column and a 1:4 mixture of ethyl acetate:hexane a6 the eluant. The photochromic 15 fractions were collected, combined and the ~ -;n~ne eluant was removed under vacuum. The crystals were isolated as described in Step 3 of Example 1. The crystalline product, 3.0 grams, melted at 110-113~C and was 99.8% pure as dete 'ned by liquid chromatographic analysis. A nuclear magnetic resonance (MMR) spectrum showed the 20 solid crystalline product to have a structure consistent with 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]-pyran.

F~XAMP!.~ 3 The procedure of Step 1 of Example 1 was followed except that 2-anisoyl chloride (14.2 grams, 0.083 moles) was used a6 the reactant instead of benzoyl chloride and the reaction mixture was stirred for one hour. 16.7 grams of the crystalline product, 5-(2-methoxybenzoyl)-2,3-dihydrobenzofuran, was recovered and used 30 in the next step. The procedure of Step 2 of Example 1 was followed except that the combined organic fraction was washed with distilled water. The yield of product cont~;n~ng 1-(2,3-dihydrobenzo-furan-5-yl)-1-(2-methoxyphenyl)-2-propyn-1-ol was 16.7 grams.

W O 95/OWK~ PCT~US94/0672~

The procedure of Step 3 of Example 1 was utilized except that the product conte;n;ng 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-methoxyphenyl)-2-propyn-1-ol and a catalytic amount of p-toluenesulfonic acid were used; the reaction mixture was heated to 5 35~C; and the oil purification procedure of Example 2 was uged. The resulting crystalline product, 3.7 grams, melted at 142-144~C and was 99.5% pure as determined by liquid chromatographic analysis. A
nuclear magnetic resonance (MMR) spectrum showed the solid crystalline product to have a structure consistent wlth 10 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-methoxyphenyl)-3H-naphtho-[2,1-b]pyran.

li~lAMP~.li'. 4 The procedure of Step 1 of Example 1 wa6 utilized except 15 that 2-fluorobenzoyl chloride (13.2 grams, 0.083 mole) was used as the reactant instead of benzoyl chloride, the mixture was stirred for one hour, and the combined organic fraction was back extracted with distilled water. 19.5 grams of product cont~ing 5-(2-fluorobenzoyl)-2,3-dihydrobenzofuran was recovered. The 20 procedure of Step 2 of Example 1 was followed except that 5-(2-fluorobenzoyl)-2,3-dihydrobenzofuran (5 grams, 0.02 mole) was used and the combined organic fraction was washed with distilled water. The yield of product, a yellow oil cont~n~ng 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-fluorophenyl)-2-propyn-1-ol, was 25 4.3 grams.
The procedure of Step 3 of Example 1 was utilized except that 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-fluorophenyl)-2-propyn-1-ol (4.3 grams) from Step 2, 3-acetoxy-2-naphthol (3.3 grams, 0.016 mole), and a catalytic amount of p-toluenesulfonic acid were used;
30 the reaction mixture was heated to 45~C; and the oil purification procedure of Example 2 was used. The resulting crystalline product, 4.6 grams, melted at 156-157~C and was 99.0% pure as determined by liquid chromatographic analysis. A nuclear magnetic resonance (MMR) spectrum 6howed the solid cry6talline product to have a structure 35 consistent with 5-acetoxy-3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluoro-phenyl)-3H-naphtho[2,1-b]-pyran.

~vo g5lOWK~ 21~ ~9 ~ 9 PCT~US94/06725 ~XA~P~ 5 The procedure of Step 1 of Example 1 was followet except that 2-fluorobenzoyl chloride (13.2 grams, 0.083 mole) wa8 uset as 5 the reactant instead of benzoyl chloride and the mixture was stirred for one hour. 16.0 grams of the product, 5-(2-fluorobenzoyl)-2, 3-dihydrobenzofuran, was recovered. The procedure of Step 2 of Example 1 was followed using 5-(2-fluorobenzoyl)-2,3-dihydrobenzo-furan (12.5 grams, 0.051 mole) from Step 1. The yield of product, 10 containing 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-fluoro-phenyl)-2-propyn-1-ol, was 11.0 grams.
The procedure of Step 3 of Example 1 was utilized except thst 1-(2,3-dihydrobenzofuran-5-yl)-1-(2-fluorophenyl)-2-propyn-1-ol (5.0 grams) from Step 2, 6-methoxy-2-hydroxynaphthalene, and a 15 catalytic amount of p-toluenesulfonic acid were used; the reaction mixture wa6 heated to 35~C and stirred for 1.5 hour8; and the oil purification procedure of Example 2 was used. The resulting crystalline product, 4.3 grams, melted at 164-167~C and was 95.0%
pure as determined by liquid chromatographic analysis. A nuclear 20 magnetic resonance (NMR) spectrum showed the solid crystalline product to have a structure consistent with 8-methoxy-3-(2,3-dihydro-benzofuran-5-vl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b] pyran.

FXA1~PT.F. 6 Step 1 2,5-dimethylphenol (30.0 grams, 0.25 mole) was added to a reaction flask cont~;n~ng 300 milliliters of ethyl alcohol and 17.0 grams (0.3 mole) of potassium hydroxide. Allyl bromide (36.3 grams, 0.3 mole) was added slowly to the stirred solution over a period of 30 15 minutes. The reaction mixture was refluxed in a nitrogen atmosphere for four hours. The excess solvent was removed under vacuum and the residual solid was dissolved in 200 milliliters of 5%
aqueous sodium hydroxide and extracted with three portions of W O 95/OWK~ PCTrUS94/06725 2~ 6~49 methylene chloride, about 100 milliliters each. The organic extracts were combined, dried over magnesium 6ulfate, and reduced under vacuum to yield 33.3 grams of a yellow oil cont~njng the desired product, 2,5-dimethylphenyl allyl ether.

Step 2 2,5-dimethylphenyl allyl ether (33.3 grams, 0.21 mole) from Step 1 was added to a reaction flask equipped with a water condenser and heated to 195~C with stirring under a nitrogen atmosphere.
10 After 2 hours, the temperature was reduced to 140~C and several drops of dodecylbenzenesulfonic acid were added. The reaction mixture was slowly heated to 195~C and held there for 3 hours. The reaction mixture was cooled and dissolved in 5% aqueous sodium hydroxide. The resulting mixture was extracted with three 100 15 milliliter portions of methylene chloride. The organic extracts were combined, dried over magnesium sulfate and Leduced under vacuum. The resulting product was distilled at a head temperature of 80~C under a reduced pressure of 6 mm Hg to yield 11.0 grams of a clear colorless oil. A nuclear magnetic spectrum (MMR) showed the 20 product to have a structure consistent with 2,3-dihydro-2,4,7-tri-methylbenzofuran.

Step 3 2,3-dihydro-2,4,7-trimethylbenzofuran (5.0 grame, 0.031 25 mole) from Step 2 was added to a reaction flask cont~n~ng 300 milliliters of methylene chloride and 5.3 grams (0.031 mole) of p-anisoyl chloride. Aluminum chloride (5.0 grams, 0.037 mole) was added slowly to the stirred solution. After 1.5 hours the reaction mixture was dissolved in 20Z aqueous hydrochloric acid and stirred 30 for 10 minutes. The organic layer was separated and the aqueous layer was washed once with 100 milliliters of methylene chloride.
The organic extracts were combined, washed with about 200 milliliters of distilled water, separated, and dried over magnesium -vo 95/~K~ ~ i 6 4 94 9 PCTrUS94/06725 sulfate. The solvent, methylene chloride, was removed under vacuum to yield 7.0 gram6 of product cont~ining the desired ketone, 5-(4-methoxybenzoyl)-2,4,7-trimethyl-dihydrobenzofuran.

Step 4 5-(4-methoxybenzoyl)-2,4,7-trimethyldihydrobenzofuran (7.0 grams, 0.024 mole) from Step 3 was added to a reaction flask cont~ining 300 milliliters of tetrahydrofuran saturated with acetylene. 8.1 grams of a 18 weight percent solution of sodium 10 acetylide in xylene/light mineral oil (0.028 mole of sodium acetylide) wa6 added to the 6tirred solution. After 72 hours the reaction mixture was dissolved in 10% aqueous hydrochloric acid and extracted with three portions of methylene chloride, about 100 milliliters each. The organic extracts were combined and dried over 15 magnesium sulfate. The methylene chloride wa6 removed under vacuum. The product cont~n~ng 1-(2,3-dihydro-2,4,7-trimethyl-benzofuran)-5-yl-1-(4-metho~y~henyl)-2-propyn-1-ol wa6 u6ed directly in the next step.

Step 5 1-(2,3-dihydro-2,4,7-trimethylbenzofuran)-5-yl-1-(4-methoxyphenyl)-2-propyn-1-ol (5.0 grams) from Step 4 was added to a reaction flask contp~n~ng 300 milliliters of benzene and 2.3 grams (0.016 mole) of 2-hydroxynaphthalene. A catalytic amount of 25 p-toluenesulfonic acid was added to the stirred solution and the mixture was heated to 35~C under a nitrogen atmosphere. After 1.5 hours, the reaction mixture was dissolved in 20% aqueous sodium hydroxide and extracted with three portions of methylene chloride, about 100 milliliters each. The organic extracts were combined and 30 dried over magne6ium sulfate. The methylene chloride was removed under vacuum. The product was purified using a silica gel column and a 1:4 mixture of ethyl acetate:hexane as the eluant. The photochromic fractions were combined and the 1~ ~ining eluant was removed under vacuum. The residual oil was crystallized from hexane W O 95/ONK~ PCT~US94/06725 ~ ~ 6 ~ g l~3 - 24 -to yield 200 mg. of the de6ired photochromic compound. The crystalline product melted at 162-164~C and was 98.8% pure a8 determined by liquid chromatographic analysis. A nuclear magnetic re60nance (MMR) spectrum showed the solid crystalline product to 5 have a structure consistent with 3-(4-methoxyphenyl)-3-(2,4,7-tri-methyldihydrobenzofuran-5-yl)-3H-naphtho[2,1-b]pyran.

FXAMPT.F. 7 2-methyldihydrobenzofuran was prepared by the method 10 described in Example 6, Steps 1 and 2, using phenol instead of 2,5-dimethyl phenol in Step 1. For further information respecting the synthesis, see Org~nic R~ction~, Volume II, pages 26 and 27.
The procedures of Steps 1, 2, and 3 of Example 1 were followed using 2-methyldihydrobenzofuran in place of 2,3-dihydrobenzofuran in 15 Step 1. The resulting product was 98.6% pure as determined by liquid chromatographic analysis. A nuclear magnetic resonance (MMR) spectrum showed the product to have a structure consistent with 3-(2-methyldihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho-[2,1-b]pyran.

FXAMP~.F 8 The procedure of Step 1 of Example 1 was utilized except that 2-fluorobenzoyl chloride (5.0 grams, 0.032 mole) was used instead of benzoyl chloride; 1,4-benzodioxan (4.4 grams, 0.032 mole) 25 was used instead of 2,3-dihydrobenzofuran; and the reaction mixture was stirred for 1 hour. 8.0 grams of the white crystalline product, 5-(2-fluorobenzoyl)-1,4-benzodioxan, was recovered. The procedure of Step 2 of Example 1 was followed except that 5-(Z-fluoro-benzoyl)-1,4-benzodioxan (8.0 grams, 0.031 mole) was used and the 30 reaction mixture was stirred for 20 hours. The yield of product containing 1-(1,4-benzodioxan-6-yl)-1-(2-fluorobenzoyl)-2-propyn-l-ol wa6 7.0 grams.

~o gS/O~K~ 4 9 PCT~US94/06725 The procedure of Step 3 of Example 1 was utilized except that product contQ1n~ng 1-(1,4-benzodioxan-6-yl)-1-(2-fluoro-benzoyl)-2-propyn-1-ol (7.0 grams) from Step 2, 2-naphthol (3.6 grams), and a catalytic amount of p-toluenesulfonic acid were used;
5 the mixture was stirred for 2 hours; and the oil purification procedure of Example 2 was used. The resulting crystalline product, about 0.5 gram, melted at 143-147~C and was 97.3% pure as determined by liquid chromatographic analysi6. A nuclear magnetic resonance (MMR) spectrum showed the solid crystalline product to have a 10 structure consistent with 3-(1,4-benzodioxan-6-yl)-3-(2-fluoro-phenyl)-3H-naphtho[2,1-b]pyran.

~XAMP!.~ 9 Step 1 Piperonal (10.0 grams, 0.067 moles) was added to a reaction flask cont~n~ng 100 milliliters of tetrahydrofuran. Phenyl magnesium bromide (0.08 moles) was added slowly and the resulting mixture was heated to 66~C and stirred for 1 hour under a nitrogen atmosphere. The reaction mixture was added to a 5 percent aqueous 20 hydrochloric acid and ice solution. The organic layer was separated and the aqueous layer was washed with three 100 milliliter port~ons of methylene chloride. The organic portions were combined and dried over magnesium sulfate. The residual methylene chloride was removed under vacuum. About 15.0 grams of a white/yellow oil product was 25 recovered. A nuclear magnetic resonance (NMR) spectrum showed the product to be consistent with alpha-phenyl-1,3-benzodioxole-5-methanol.

Step 2 Alpha-phenyl-1,3-benzodioxole-5-methanol (10.0 grams, 0.044 mole) from Step 1 was dissolved in a reaction flask cont~n~ng 300 milliliters of methylene chloride and pyridinium dichromate (25.0 grams, 0.066 mole) was added. After 16 hours at room temperature and under a nitrogen atmo6phere, the reaction mixture was diluted W O 95/00866 PCTrUS94/06725 2164~ l~

with diethyl ether and vacuum filtered to remove the solid~. The liquid portion was subjected to evaporation to yield 8.3 grams of a slightly viscous off white oil. A nuclear magnetic resonance (NMR) spectrum showed the product to have a structure consistent with 5 5-benzoyl-1,3-benzodioxole.

Step 3 The procedure of Step 2 of Example 1 was followed except that 5-benzoyl-1,3-benzodioxole (8.3 grams) was used as a reactant 10 instead of 5-(benzoyl)-2,3-dihydrobenzofuran and after the reaction mixture was stirred for 22 hours at room temperature, the pH was reduced to about 2Ø The yield of product cont~n~ng 1-(1,3-benzodioxole-5-yl)-1-phenyl-2-propyn-1-ol was 9.0 grams.

Step 4 1-(1,3-benzodioxole-5-yl)-1-phenyl-2-propyn-1-ol (3.5 grams, 0.014 mole) from Step 3 and 2-naphthol (2.0 grams, 0.014 mole) were added to a reaction flask containing 300 milliliters of toluene. A catalytic amount of p-toluenesulfonic acid was slowly 20 added and the reaction mixture was stirred for 2 hours at room temperature under a nitrogen atmosphere. Afterwards, the reaction mixture was added to 200 milliliters of 20~ aqueous sodium hydroxide and washed. The organic layer was separated and dried over magnesium sulfate. The solids were filtered and the resulting oil 25 was purified on a silica gel column using chloroform as the eluant.
The resulting orange oil was induced to crystallize by dissolving it in a hexane/ether mixture and cooling the mixture in a dry ice/acetone bath. The resulting crystals were collected by vacuum filtration. The crystalline product, about 4.1 grams, melted at 30 168-170~C and was 99.8% pure as determined by liqu~d chromatograph~c analysis. A nuclear magnetic resonance (MMR) spectrum showed the solid crystalline product to have a structure consistent with 3-(1,3-benzodioxole-5-yl)-3-phenyl-3H-naphtho[2,1-b]pyran.

~~'0 95lO~KbPCTrUS94106725 ~6~43 COMPARATIVE _xAMpT F 1 1,1-diphenyl-2-propyn-1-ol (20.8 grams, 0.1 mole) wa6 added to a reaction flask containing 200 milliliters of benzene and 15 grams of 2-naphthol. The reaction mixture was warmed to 55~C and 5 after all of the 2-naphthol was dissolved, 0.25 grams of p-toluenesulfonic acid was added to the stirred reaction mixture.
The mixture changed from light tan to dark black, became exothermic, and the temperature rose to 70~C. After a few minutes, the reaction mixture lightened and began to cool. After 30 minutes, the reaction 10 mixture was poured into 100 milliliters of 10 percent aqueous sodium hydroxide and shaken. The organic phsse was washed once with 10 percent aqueous 60dium hydroxide and then washed with water. The solvent, benzene, was removed on a rotary evaporator. The resulting light tan solid residue was slurried with 100 milliliters of hexane 15 and filtered. The filtered solid was washed again with 100 milliliters of hexane and dried to provide 18.4 grams of the product, 3,3-diphenyl-3H-naphtho[2,1-blpyran. The solid product had a melting point of 156-158~C and wa8 98 percent pure a8 determined by liquid chromatographic analysis.

CO~PARATIVF. FXAMPT-F. 2 Anisole (10.8 grams, 0.1 mole) and benzoyl chloride (14 grams, 0.1 mole) were dissolved in 200 milliliters of hexane and stirred at room temperature. Anhydrous al~ ' chloride, 15 grams, 25 was added slowly to the reaction mixture over a period of 15 minutes. The reaction mixture was stirred an additional 15 minute~. The hexane was decanted and the resulting viscous residue was carefully hydrolyzed with 200 milliliters of a mixture of ice and dilute hydrochloric acid. The organic fraction was taken up in 30 dichloromethane and the resulting solution was washed with water.
Dichloromethane was removed on a rotary evaporator leaving an oil product that solidified on s~nd;ng. The solidified product was broken-up, wa6hed with two 50 milliliter portions of pentane, and dried, yielding 4-methoxybenzophenone.

W O 95/O~K~ PCTrUS94/06725 ~ 1 6 ~ g ~ 28 -10 grams of this 4-methoxybenzophenone was converted to the propargyl alcohol by the procedure de~cribed in Step 2 of Example 1. MMR analysis of the resulting product showed it to be a mixture of compounds having structures consistent with 5 1-phenyl-1(4-methoxyphenyl)-2-propyn-1-ol and the starting ketone, 4-methoxybenzophenone, in a ratio of 3:1.
The crude propargyl alcohol was added to a reaction flask containing a 61urry of 5 grsms of 2-naphthol, 40 grams of anhydrous acid alumina and 200 milliliters of toluene. The resulting reaction 10 mixture was heated to reflux for 30 minutes, cooled, snd filtered.
The alumina was washed two times with 100 milliliter portions of hexane. The toluene and hexane fractlons were combined and the organic solvents were removed on a rotary evaporator. The resulting product was an orange oil that was induced to crystallize by 15 dissolving it in a mixture of hexane and diethyl ether and then cooling the solution in a dry ice/acetone bath. The product crystals were washed with diethyl ether and dried to yield 1.4 grsms of a product having a melting point of 149-150~C. A nuclear magnetic resonance (NMR) spectrum showed the solid product to have a 20 structure consistent with 3-phenyl-3(4-methoxyphenyl)-3H-naphtho[2,1-b]pyran.

Cor1p~RATIvF: FXAMP~.F, 3 The procedure~ of Steps 1 and 2 of Example 1 were followed 25 except that anisole was used instead of 2,3-dihydrobenzofuran and 2-fluorobenzoyl chloride was used instesd of benzoyl chloride in Step 1. The resulting product contained 1-(4-methoxy-3-methyl-phenyl)-1-(2-fluorophenyl)-2-propyn-1-ol. The procedure of Step 3 of Example 1 was utilized except that 1-(4-methoxy-3-methylphenyl)-30 1-(2-fluorophenyl)-2-propyn-1-ol (5.5 grams, 0.02 mole) from the previous 6tep, 2-naphthol (3.0 gram~), and a catalytic amount of p-toluenesulfonic acid were used; and the reaction mixture was heated to 35~C and stirred for several hours.

~o gS/O~K~ 2 ~ 6~ PCTrUS94/06725 The resulting oil product was purified on a silica gel column using a 1:5 mixture of ethyl scetate:hexane as the fir6t eluant followed by a 1:1 mixture of chloroform:hexane as the second eluant. The filtrate was collected and the solvent was removed to 5 yield 2.0 grams of a solid product. The solid product had a melting point of 98~C and was 99% pure as determined by liquid chromatographic analysis. A nuclear magnetic resonance (NMR) spectrum showed the solid product to have a structure consistent with 3-(4-methoxy-3-methylphenyl)-3-(2-fluorophenyl)-3H-naphtho-10 [2,1-b]pyran.

Example 10 pArt A
The naphthopyran prepared in Example 9 was incorporated 15 into an ethyl cellulose resin by the following procedure. 25 milligrams of the photochromic cr ~Q~--d was added to 2.0 grams of a 10 weight percent ethyl cellulose solution in toluene. The naphthopyran compound was dissolved by warming and 6tirring on a steam bath. Approximately 2.0 grams of the resultant solution was 20 deposited on the edge of a 75 by 25 millimeter (mm) glass slide.
Using a draw down bar, an 8 mm layer of photochromic resin solution was placed evenly on the slide and permitted to dry.

pArt B
Further testing was done on selected naphthopyrans that were imbibed by thermal transfer into test squares of a homopolymer of diethylene glycol bis(allyl carbonate) by the following procedure. Each naphthopyran was dissolved into toluene solvent to form a 4 weight percent solution of the compound. A piece of No. 4 30 Whatman filter paper was 6aturated with the naphthopyran solution and allowed to air dry. The dried filter paper was placed on one side of the polymer test square, which measured 118 inch (0.3 centimeter) x 2 inch (5.1 centimeters) x 2 inch (5.1 centimeters).
A piece of untreated filter paper was placed on the other side of 35 the polymer test square and the resulting sandwich placed between W O 95/OWK6 PCTrUS94/06725 21~4~43 two plate6 of flat aluminum metal plates. The entire assembly was then placed in a 155~C oven for a time sufficient to the ~1 ly tran~fer the naphthopyrsn into the polymer test 6quare. Residence times in the oven were ad~usted to imbibe comparable amounts of the 5 naphthopyran c~ ,,o~lds in order to yield a comparable W absorbance at 347 nm. The imbibed test squares were washed with acetone after removal from the oven.

Part C
Both sets of polymer te6t samples were tested for photochromic response rates on an optical bench. The samples were illuminated by a 150 watt Xenon lamp fitted with a copper sulfate bath and a neutral density filter at an intensity of about one sun.
A second beam of light provided by a filtered tungsten lamp arranged 15 to pas~ through the sample area expo~ed by the W source was used to monitor changes in transmission of the sample over different wavelength ranges in the visible region of the spectrum. The intensity of the monitoring beam after passing through the sample was measured by means of an IL-1500 r8diometer equipped with a 20 silicon detector head and matching filters.
The ~ OD/Min, which represents the sensitivity of the photochromic cc po~d's response to W light, was measured using photopic filters on the silicon detector. The response of the filtered detector approximated the luminosity curve. The ~ OD/Min 25 was measured over the first five (5) seconds of W exposure, then expressed on a per minute basis. The saturation optical density (OD) was taken under identical conditions as the ~ OD/Min, except W exposure was continued for 20 minutes for the examples in Table 1 and for 15 minutes for the examples in Table 2. The lambda max 30 reported in Tables 1 and 2 is the wavelength in the visible spectrum at which the ~ absorption of the activated (colored) form of the photochromic compound in poly (diethylene glycol bis (allyl carbonate)) in Table 1 and in ethyl cellulose resin in Table 2 occurs. The Bleach Rate T 1/2 i8 the time interval in seconds for 2~ 6~9~9 vo 95/~WK~ PCT~US94/06725 the absorbance of the activated form of the naphthopyran in the te6t polymers to reach one half the highe6t absorbance at room temperature (72~F, 22.2~C) after removal of the source of activatin~
light. Results are tabulated in Tables 1 and 2.

TAR~.F 1 Polyrdiethyl~ne ~lycol bis(~llyl r~rbnn~te)l Samples COMPOUND LAMBDA~ OD/Min ~ OD @ BLEACH RATE
EXA~PLE M~xS~SITIVITY SATURATION T 1/2 (S~C.) 1 478 nm 0.62 0.20 33 2 475 D 0.86 0.90 179 3 482 nm 1.02 1.76 >600 4 490 nm 0.31 0.66 368 488 nm 0.91 1.73 624 6 485 nm 0.53 0.61 363 7 479 D O.9I 0.90 151 8 463 D 0.83 1.00 261 COMPARATIYE
MpT.F.
1 432 nm 0.87 0.36 45 2 468 D O . 66 0.25 35 3 467 D 0.96 0.97 191 a.* 476 D 0.45 1.36>30 min.

* a. Purcha6ed 2,2-diphenyl-2H-naphtho[1,2-b]pyran W O 95/OWK6 PCTrUS94/06725 9~9 TAR~.F 2 Ethyl Cellulose S~mples . .
COMPOUND LAMBDA ~ OD/Min ~ OD @ BLEACH RATE
EXAMPLE MAX SENSITIVITY SATURATION T 1/2 (SEC.) 9 459 nm 0.66 0.31 41 COMPARATIVE

10 F~ P!.F, 1 432 nm0.87 0.31 32 The data tabulated in Tables 1 and 2 ehow that all of the 15 Cc ~ow.d Examples, except Cc "owld Examples 8 and 9, have lambda max values closer to 480 nm than Comparative Examples 1, 2, and 3.
Compound Examples 8 and 9 have lambda max values much higher than Comparative Example 1 which has two phenyl groups at the 3 position of the pyran ring. Comparative Example "a" has a lamda max of 476 20 but the bleach rate is unacceptably slow for use ;n an ophthalmic lens application.
Although the present invention has been described with reference to the specific details of particular embodiments thereof, it is not intended that such details be regarded upon the scope of 25 the invention except insofar as to the extent that they are included in the accompanying claims.

Claims

I claim:

1. A naphthopyran compound represented by the following graphic formula:

wherein, (a) R1 and R2 are each C1-C10 alkyl, C5-C7 cycloalkyl, halogen, R(R')N-, or the group, -O-L, wherein R and R' are each hydrogen or C1-C3 alkyl, L is C1-C12 alkyl, phenyl(C1-C3)alkyl, C1-C3 alkylphenyl, C1-C5 alkylcarbonyl, halo(C1-C4) alkylcarbonyl, C1-C4 monoalkylaminocarbonyl, acetonyl, pyridyl, substituted or unsubstituted arylcarbonyl, said aryl group being phenyl or naphthyl, said aryl substituents being C1-C4 alkyl, C1-C4 alkoxy, halogen, C5-C7 cycloalkyl, or C1-C4 alkyl substituted C5-C7 cycloalkyl, said halogen (or halo) groups being chloro, fluoro, or bromo; and a and b are each the integers 0, 1, or 2, provided that the sum of a and b is not more than 2;
(b) B is the substituted or unsubstituted aryl group, naphthyl or phenyl, said aryl substituents being C1-C5 alkyl, halo(C1-C5)alkyl, hydroxy. C1-C5 alkoxy, C1-C4 alkoxy(C1-C4)alkyl, halogen, or R(R')N-, wherein R and R' are each hydrogen or C1-C3 alkyl, and said halogen (or halo) groups being fluorine, chlorine, or bromine; and (c) B' is selected from the groups represented by the following graphic formulae:

wherein X is oxygen or nitrogen and Y is carbon or oxygen provided that when X is nitrogen, Y is carbon; R4 and R5 are each hydrogen or C1-C5 alkyl; each R3 is a C1-C5 alkyl, C1-C5 alkoxy, hydroxy, or halogen, said halogen being chloro, fluoro or bromo, and c is an integer from 0 to 3.

2. A naphthopyran of Claim 1 wherein:
(a) R1 and R2 are each C1-C5 alkyl, C5-C6 cycloalkyl, fluorine, bromine, R(R')N-, or the group -O-L, wherein R and R' are each hydrogen or C1-C2 alkyl, L is C1-C4 alkyl, C1-C2 alkylphenyl, phenyl (C1-C2) alkyl, phenylcarbonyl, C1-C2 alkylcarbonyl, halo-(C1-C2)alkylcarbonyl, or C1-C2 monoalkylaminocarbonyl, said halo group being chloro or fluoro; and a and b are the integers; 0 or 1;

(b) B is represented by the following graphic formula:

wherein R6 is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, fluoro, or chloro, each R7 is a C1-C4 alkyl, C1-C4 alkoxy, hydroxy, chloro or fluoro, and d is an integer from 0 to 2; and (c) B' is selected from the groups represented by the following graphic formulae:

wherein X is oxygen, Y is carbon or oxygen, R4 and R5 are each hydrogen or C1-C4 alkyl, each R3 is a C1-C4 alkyl, C1-C4 alkoxy, hydroxy, or fluoro, and c is an integer from 0 to 2.

3. A naphthopyran compound of Claim 2 wherein R1 and R2 are each C1-C3 alkyl, fluorine or the group -O-L, wherein L is acetyl, benzoyl, methyl, or methylaminocarbonyl; B is phenyl or substituted phenyl, said phenyl substituents being fluoro, methyl, or methoxy; B' is 2,3-dihydrobenzofuran-5-yl, 2-methyldihydrobenzofuran-5-yl, indoline-5-yl, 1,2,3,4-tetrahydroquinoline-6-yl, chroman-6-yl, or 1,3-benzodioxole-5-yl; and R3, R4, and R5 are each hydrogen or methyl, and a, b, and d are the integers 0 or 1.

4. A naphthopyran compound selected from the group consisting of:
(a) 3-(2,3-dihydrobenzofuran-5-yl)-3-phenyl-3H-naphtho-[2,1-b]pyran;
(b) 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;
(c) 3-(2,3-dihydrobenzofuran-5-yl)-3-(2-methoxyphenyl)-3H-naphtho[2,1-b]pyran;
(d) 3-(2-methyldihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;
(e) 8-methoxy-3-(2,3-dihydrobenzofuran-5-yl)-3-(2-fluorophenyl)-3H-naphtho[2,1-b]pyran;
(f) 3-(4-methoxyphenyl)-3-(2,4,7-trimetby-1-2,3-dihydrobenzofuran-5-yl)-3H-naphtho[2,1-b]pyran; and (g) 3-(1,3-benzodioxole-5-yl)-3-phenyl-3H-naphtho-(2,1-b)pyran.

5. A photochromic article comprising an organic host material and a photochromic amount of a naphthopyran compound represented by the following graphic formula:

wherein, (a) R1 and R2 are each C1-C10 alkyl, C5-C7 cycloalkyl, halogen, R(R')N-, or the group, -O-L, wherein R and R' are each hydrogen or C1-C3 alkyl, L is C1-C12 alkyl, phenyl(C1-C3)alkyl, C1-C3 alkylphenyl, C1-C5 alkylcarbonyl, halo(C1-C4)alkylcarbonyl, C1-C4 monoalkylaminocarbonyl, acetonyl, pyridyl, substituted or unsubstituted arylcarbonyl, said aryl group being phenyl or naphthyl, said aryl substituents being C1-C4 alkyl, C1-C4 alkoxy, halogen, C5-C7 cycloalkyl, or C1-C4 alkyl substituted C5-C7 cycloalkyl, said halogen (or halo) groups being chloro, fluoro, or bromo; and a and b are each the integers 0, 1, or 2, provided that the sum of a and b is not more than 2;
(b) B is the substituted or unsubstituted aryl group, naphthyl or phenyl, said aryl substituents being C1-C5 alkyl, halo(C1-C5)alkyl, hydroxy, C1-C5 alkoxy, C1-C4 alkoxy(C1-C4)alkyl, halogen, or R(R')N-, wherein R and R' are each hydrogen or C1-C3 alkyl, and said halogen (or halo) groups being fluorine, chlorine, or bromine; and (c) B' is selected from the groups represented by the following graphic formulae:

wherein X is oxygen or nitrogen and Y is carbon or oxygen provided that when X is nitrogen, Y is carbon; R4 and R5 are each hydrogen or C1-C5 alkyl; each R3 is a C1-C5 alkyl, C1-C5 alkoxy, hydroxy, or halogen, said halogen being chloro, fluoro, or bromo, and c is an integer from 0 to 3.

6. The photochromic article of Claim 5 wherein the organic host material is selected from the group consisting of polyacrylates, cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), polycarbonate, polyurethane, poly(ethylene terephthalate), polystyrene, copoly(styrene-methylmethacrylate), copolytstyrene-acrylonitrile), polyvinylbutyral and polymers of members of the group consisting of polyol(allyl carbonate) monomers, polyfunctional acrylate monomers, and diallylidene pentaerythritol monomers.

7. The photochromic article of Claim 6 wherein:
(a) R1 and R2 are each C1-C5 alkyl, C5-C6 cycloalkyl, fluorine, bromine, R(R')N-, or the group -O-L, wherein R and R' are each hydrogen or C1-C2 alkyl, L is C1-C4 alkyl, C1-C2 alkylphenyl, phenyl (C1-C2)alkyl, C1-C2 alkylcarbonyl, halo(C1-C2)alkylcarbonyl, or C1-C2 monoalkylaminocarbonyl, said halo group being chloro or fluoro; and a and b are the integers 0 or 1;
(b) B is represented by the following graphic formula:

wherein R6 is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, fluoro, or chloro, each R7 is a C1-C4 alkyl, C1-C4 alkoxy, hydroxy, chloro, or fluoro, and d is an integer from 0 to 2; and (c) B' is selected from the groups represented by the following graphic formulae:

wherein X is oxygen, Y is carbon or oxygen, R4 and R5 are each hydrogen or C1-C4 alkyl, each R3 is a C1-C4 alkyl, C1-C4 alkoxy, hydroxy, or fluoro, and c is an integer from 0 to 2.

8. The photochromic article of Claim 7 wherein R1 and R2 are each C1-C3 alkyl, fluorine or the group -O-L, wherein L is acetyl, benzoyl, methyl, or methylaminocarbonyl; B is phenyl or substituted phenyl, said phenyl substituents being fluoro, methyl, or methoxy;
B' is 2,3-dihydrobenzofuran-5-yl;
2-methyldihydrobenzofuran-5-yl, indoline-5-yl, 1,2,3,4-tetrahydroquinoline-6-yl, chroman-6-yl, or 1,3-benzodioxole-5-yl; and R3, R4, and R5 are each hydrogen or methyl, and a, b, and d are the integers 0 or 1.

9. The photochromic article of Claim 8 wherein the organic host material is a solid transparent homopolymer or copolymer of diethylene glycol bis(allyl carbonate), carbonate-linked resin derived from 4,4'- dioxydiphenol-2-2-propane and phosgene, poly(methylmethacrylate), polyvinylbutyral, or a polyurethane.

10. The photochromic article of Claim 9 wherein the photochromic compound is present in an amount of from about 0.15 to 0.35 milligrams per square centimeter of organic host material surface to which the photochromic substance(s) is incorporated or applied.

11. The photochromic article of Claim 10 wherein the article is a lens.

12. A photochromic article comprising a solid transparent polymerized organic host material and a photochromic amount of each of (a) a first photochromic substance selected from the group consisting of spiro (indoline) naphthoxazines, spiro(indoline) pyridobenzoxazines, and spiro(indoline) benzoxazines, and benzopyrans or naphthopyrans having a nitrogen-containing substituent in the 2-position of the pyran ring, and (b) a second photochromic substance selected from naphthopyran compounds represented by the following graphic formula:

wherein, (a) R1 and R2 are each C1-C10 alkyl, C5-C7 cycloalkyl, halogen, R(R')N-, or the group, -O-L, wherein R and R' are each hydrogen or C1-C3 alkyl, L is C1-C12 alkyl, phenyl (C1-C3)alkyl, C1-C3 alkylphenyl, C1-C5 alkylcarbonyl, halo(C1-C4)alkylcarbonyl, C1-C4 monoalkylaminocarbonyl, acetonyl, pyridyl, substituted or unsubstituted arylcarbonyl, said aryl group being phenyl or naphthyl, said aryl substituents being C1-C4 alkyl, C1-C4 alkoxy, halogen, C5-C7 cycloalkyl, or C1-C4 alkyl substituted C5-C7 cycloalkyl, said halogen (or halo) groups being chloro, fluoro, or bromo;
and a and b are each the integers 0, 1, or 2, provided that the sum of a and b is not more than 2;
(b) B is the substituted or unsubstituted aryl group, naphthyl or phenyl, said aryl substituents being C1-C5 alkyl, halo(C1-C5)alkyl, hydroxy, C1-C5 alkoxy, C1-C4 alkoxy (C1-C4)alkyl, halogen, or R(R')N-, wherein R and R' are each hydrogen or C1-C3 alkyl, and said halogen (or halo) groups being fluorine, chlorine, 35 or bromine; and (c) B' is selected from the group6 represented by the following graphic formulae:
wherein X is oxygen or nitrogen and Y is carbon or oxygen provided that when X is nitrogen, Y is carbon; R4 and R5 are each hydrogen or C1-C5 alkyl; each R3 is a C1-C5 alkyl, C1-C5 alkoxy, hydroxy or halogen, said halogen being chloro, fluoro, or bromo, and c is an integer from 0 to 3.

13. The photochromic article of Claim 12 wherein the organic host material is selected from the group consisting of polyacrylates, cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidene chloride), polycarbonate, polyurethane, poly(ethylene terephthalates, polystyrene, copoly(styrene-methylmethacrylate), copoly(styrene-acrylonitrile), polyvinylbutyral and polymers of members of the group consisting of polyol(allyl carbonate) monomers, polyfunctional acrylate monomers, and diallylidene pentaerythritol monomers.

14. The photochromic article of Claim 13 wherein:
(a) R1, and R2 are each C1-C5 alkyl, C5-C6 cycloalkyl, fluorine, bromine, R(R')N-, or the group -O-L, wherein R and R' are each hydrogen or C1-C2 alkyl, L is C1-C4 alkyl, C1-C2 alkylphenyl, phenyl(C1-C2)alkyl, phenylcarbonyl, C1-C2 alkylcarbonyl, halo(C1-C2)alkylcarbonyl, or C1-C2 monoalkylaminocarbonyl, said halo group being chloro or fluoro; and a and b are the integers 0 or 1;
(b) B is represented by the following graphic formula:

wherein R6 is hydrogen, C1-C4 alkyl, C1-C4 alkoxy, fluoro, or chloro, each R7 is a C1-C4 alkyl, C1-C4 alkoxy, hydroxy, chloro, or fluoro, and d is an integer from 0 to 2; and (c) B' is selected from the groups represented by the following graphic formulae:

wherein X is oxygen, Y is carbon or oxygen, R4 and R5 are each hydrogen or C1-C4 alkyl, each R3 is C1-C4 alkyl, C1-C4 alkoxy, hydroxy, or fluoro, and c is an integer from 0 to 2.

15. The photochromic article of Claim 14 wherein R1 and R2 are each C1-C3 alkyl, fluorine or the group -O-L, wherein L is acetyl, benzoyl, methyl, or methylaminocarbonyl; B is phenyl or substituted phenyl, said phenyl substituents being fluoro, methyl, or methoxy; B' is 2,3-dihydrobenzofuran-5-yl; 2-methyldihydrobenzofuran-5-yl, indoline-5-yl, 1,2,3,4-tetrahydroquinoline-6-yl, chroman-6-yl, or 1,3-benzodioxide-5-yl;
and R3, R4, and R5 are each hydrogen or methyl, and a, b, and d are the integers 0 or 1.

16. The photochromic article of Claim 15 wherein the organic host material is a solid transparent homopolymer or copolymer of diethylene glycol bis(allyl carbonate), carbonate-linked resin derived from 4,4'-dioxydiphenol-2-2-propane and phosgene, poly(methylmethacrylate), polyvinylbutyral, or a polyurethane.

17. The photochromic article of Claim 16 wherein the photochromic compound is present in an amount of from about 0.15 to 0.35 milligrams per square centimeter of organic host material surface to which the photochromic substance(s) is incorporated or applied.

18. The photochromic article of Claim 17 wherein the weight ratios of the first photochromic substance to the naphthopyran compound is from about 1:3 to about 3:1.

19. The photochromic article of Claim 18 wherein the article is an ophthalmic lens.