ASYMMETRIC MONOCYCLIC SUBSTITUENT.

COMPOSITIONS AND ARTICLES CONTAINING THEM

The present invention concerns novel compounds ofthe spiroxaziπe type presenting, in particular, photochromic properties It also concerns the photochromic compositions and ophthalmic articles (e g., lenses) which contain spiroxazines

The photochromic compounds are capable of changing color due to the influence of a poly- or monochromatic light (e g , UV) and they are capable of covering their initial content, when the irradiation with light stops, or due to the influence of a poly- or monochromatic light which is different from the first light, or due to the influence ofthe temperature and/or of a poly- or monochromatic light which is different from the flrst one. These photochromic compounds are applied in various fields, for example, for the manufacture of ophthalmic lenses, contact lenses, some sunshades, filters, optics for cameras or photography apparatuses or other optical devices or observation devices, glass partitions, decorative objects, elements of displays or for the storage of information by optical inscription (encoding). In the field of ophthalmic optics, and in particular in the field of eyeglasses, a photochromic lens, comprising one or more photochromic compounds, must present

- a high transmission in darkness or in the absence of sunlight,

- a low transmission (high colorability) when exposed to irradiation by sunlight, • an appropriate kinetics of coloration and decoloration, - a tint which is acceptable to the consumer (gray or chestnut brown, preferably), with, preferably, maintenance ofthe selected tint during the course ofthe coloration and the decoloration ofthe lens,

- a maintenance ofthe performances ofthe characteristics in a temperature range of 0-40° C,

- a high durability, because the objectives intended are sophisticated and, therefore expensive, corrective lenses

These lens characteristics are in fact determined by the active photochromic compounds which, in addition, must be perfectly compatible with the organic or mineral support which constitutes the lens.

Moreover, it should be noted that the obtention of a gray or chestnut brown tint may require the use of at least two photochromes of different colors, that is having distinct maximum absoφtion wavelengths in the visible range (λ,,,,.). This association thus imposes still other requirements on photochromic compounds. In particular, the kinetics of coloration and decoloration ofthe two or more associated active photochromic compounds must be essentially identical. The same applies to their stability over time and, also, to their compatibility with a plastic or mineral support.

Among the numerous photochromic compounds described in the prior art, one can cite the indolinospironaphtoxazines described in U S Patent Nos 3,578,602, 3,562, 172, 4,215,010; European Patent Nos. 0,171,909, 0,313,941 , French Patent No.

2,647,789, European Patent No 0,600,669.

The group R, of these molecules represent linear or branched alkyls, alkyiaryls or alicyclics These compounds are considered to meet the specifications defined above In fact, while these compounds have indeed one or more ofthe wanted basic properties, such as high transmission in darkness, high colorability when exposed to sun radiation, absorption in the blue or violet [spectrum] (570-630 nm), rapid kinetics of coloration and decoloration, all the compounds described to this day do not have the complete combination ofthe desired properties that are required for the production of satisfactory articles, which can be manufactured industrially.

Whereas the prior art teaches how to modify the absoφtion band by the addition of substituents to the different positions ofthe rings and also how to modify the kinetics

of decoloration, in contrast, it does not teach how to increase the colorability of these molecules without increasing the residual coloration in the inactivated state and, above all, on how to make them photochemically stable so as to allow their use on an industrial scale Indeed, without a high stability, these expensive molecules, introduced into a sophisticated lens, cannot be used.

It is the merit ofthe applicant to have found unexpectedly that the presence of an asymmetric monocyclic substituent group on the nitrogen atom ofthe indoline or portion ofcertain indolinospiroxazines allows the solution ofthe problem ofthe residual coloration and ofthe colorability, which is essential for the indicated applications The originality of the invention resides in the surprising effect ofthe asymmetric monocyclic group which increases the colorability ofthe spiroxazines, without increasing their residual coloration, while ensuring a good photostability.

Thus, the present invention concerns a compound, in particular, a photochromic compound, having the following General Formula (I):

in which,

- R ¹ is an asymmetric aliphatic monocyclic group which is directly connected to the nitrogen atom, having from 5 to 7 members, and possibly comprising at least one heteroatom, and having the Formula

where I = 1-12, R* represents H or an alkyl, alkoxy. dialkylamino, alkyl ester or CN group, provided that at least one ofthe R ⁹ is not H.

- R ² , R ^J are identical or different and they represent an alkyl group, linear or branched, of 1-12 carbon atoms, an alkenyl, alkynyl. aryl, alkylaryl, cycloalkyl, R ² and

R ^J can, optionally, combine to form a carbocyclic or heterocyclic group having 5 to 10 atoms,

- R\ R ⁵ . R* and R ⁷ are identical or different and they represent

■ hydrogen, " an alkyl, cycloalkyl, alkenyl, alkynyl, aryl (preferably phenyl, naphthyl mono-, di- or trisubstituted by electron donor or acceptor groups), heteroaryl, aryloxy or aralkyl, said group being optionally halogenated,

■ a halogen, preferably F, Br, CL,

■ OR, SR, -OCOR, -COOR, with R = H, alkyl and/or cycloalkyl and/or aryl, " a (poly)ether, a (poly)amide, a (polycarbonate, a (poly)carbamate, a

(poly)urea or a (poly)ester,

■ * an amino radical which gives rise, once it is bound in (T), to a primary, secondary or tertiary amine, said amine being alkyl, aryl or aralkyl, mono- or disubstituted depending on its nature, * or an a inocyclic radical containing, optionally, one or more heteroatoms,

■ or an electron withdrawing group selected, preferably, from the group comprising CF-, CN, NO ₂ , SCN,

- where at least two ofthe radicals R*. R ⁵ , R ⁶ . R ⁷ . preferably borne by two adjacent carbon atoms, can combine to form at least one aromatic ring having 5 or 6 members or aliphatic ring having 5 to 7 members, preferably 5 or 6 members, said ring(s) comprising, optionally, at least one heteroatom, so as to form at least one heterocyclic ring, the latter being optionally substituted by one or more radicals, which may be identical or different, and have the same definition as given above for R ⁴ to R ⁷ ,

- A represents a (hetero)aromatic ring (containing, for example, at least one nitrogen atom) and possibly substituted by one or more radicals R'. which may be identical or different, and having the same definition as given above for R* to R ⁷ ,

- n is a whole number and when n > 2, two ofthe radicals R' can possibly combine to form at least one aromatic or heteroaromatic ring.

The term "asymmetric" in the expression "asymmetric aliphatic monocyclic group" signifies that the plane which is peφendicular to the ring B of group R ^l and including the segment of a straight line representing the bond between the ring B and the nitrogen atom is not a plane of symmetry for the group R ¹ , with the understanding that

this reasoning is based on the formula developed in a plane ofthe group R ¹ Specific examples of groups R ¹ are the following:

among many others.

Preferred compounds ofthe invention have the following Formula (T):

where A. and R ¹ to R ⁷ are as defined above, and D is an aromatic or aliphatic ring having 5 to 7 members, optionally comprising a heteroatom, which may or may not be substituted by one or more radicals, which may be identical or different, and have the same definition as given for R ⁴ to R ⁷

According to a particularly preferred embodiment ofthe invention, the ring A is a phenyl group and R ⁴ and R ⁵ combine to form an aromatic ring This corresponds to the foUowing

Formula (I"):

in which R ¹ to R ⁴ and R ⁶ to R ¹ are as defined above, and n and m assume the values 0 to 4.

Among the substituents which can be considered for the compounds with Formulas (I), (T) and (I") according to the invention, groups R ⁴ to R' must be considered which comprise and/or form at least one reactive function for polymerization

and/or crosslinking, selected, preferably, from the following list, alkenyl-preferabry vinyl— methacryloyi acryloyl, acryloxyalkyl, methacryloxyalkyl or epoxy.

Thus, the photochromic compounds according to the invention can be designed as monomers, of different types or not, which can react between themselves or with other comonomers, to form homopolymers and/or copolymers, which bear a photochromic group and which have the mechanical properties of macromolecules. It follows that one ofthe objects of the present invention consists of these homopolymers or copolymers comprising (co)monomers and/or of αosslinkages, consisting at least in part of photochromic compounds (I), (T) and (I") according to the invention. In the same order of ideas, the above-mentioned compounds (I), (I ¹ ) and (I") can be considered to be crosslinking agents which have reactive functions capable of allowing the formation of bridges between polymer chains which may or may not be of photochromic type. The crosslinkages, which can thus be obtained, also constitute another object ofthe present invention. Ln general, in the preceding formulas, the following designations are used, according to the invention:

- "alkyl," referring preferably to a linear or branched hydrocarbon group having from 1 to 12 carbon atoms;

- "alkoxyl," referring to a group of O-alkyl type preferably having from 1 to 10 carbon atoms,

- "aryl," referring to an aromatic hydrocarbon group containing at least 6 carbon atoms,

- "heteroaryL" referring to an aromatic hydrocarbon group comprising of at least 5 atoms, of which at least one is a heteroatom, - "aralkyl a group comprising of at least one alkyl and at least one aryl, as defined above,

- "heteroatom," atoms different from C and H, belonging preferably to the foUowing group: N, O, and S.

The photochromic compounds used which are particularly preferred in the context ofthe invention are thus, as can be concluded from the above, indolinospironaphthoxazines or indolinospirobenzoxazines

The most advantageous indolinospiroxazines include those having the Formula

where R =

n = 0, 1 or 2 and

R ² . R ³ = C.-C, alkyl*

R ⁴ = H. OMe,

R ⁶ = H, OMe or amino

R' = H, Me, OMe or CF,

It is the merit of the applicant to have disclosed these compounds, because they present particularly advantageous photochromic properties. More specifically, they have high colorability, particularly in the blue region ofthe spectrum. They are thus weU suited to combination— observing compatibility and complementarity requirements— with photochromes which absorb in the yeUow, orange, red and violet spectra, so as to obtain a broad coverage ofthe visible absorbance spectrum and thus coloration tints which are just chestnut brown or dark gray.

The sensitivity, as weU as the height and the area of their λ^, peaks in the visible range reach satisfactory values.

These compounds are also perfectly stable and compatible with support matrices made of organic polymers or of mineral materiaL both in a form included in the matrix and in the form of a coating

In solution, or in a polymer matrix, the compounds according to the invention

are colorless or slightly colored in the initial state and rapidly develop an intense coloration under UN light (365 nm) or a Ught source ofthe sun radiation type Finally, they quickly restore their initial color when the irradiation stops.

The compounds ofthe invention can be obtained by the condensation of an indoline derivative substituted with an asymmetric aliphatic monoclyclic group R ¹ and an aromatic nitroso alcohol derivative such as those described, for example, in U S. Patent Νos 3,578,602, 4,634,767, 4,913,544 and European Patent No A 600,669 This reaction can take place in solvents such as ethanol, toluene or dichloroethane.

The indoline derivatives are obtained by methods which are adapted from the literature.

Step 1 is performed according to a procedure described in Katritzky et al , Tetrahedron, 1991, Vol 47, p 2683 The nitrosation of the amine (step 2) is conducted by a reaction with sodium nitrite-hydrochloric acid and the reduαion ofthe nitroso derivative (step 3) is conduαed by the reaαion of LiAlH _« in THF (Fridraan et al , Russian Chemical Reviews, 1971 , 40( 1 ), 34) The last step ofthe synthesis (4) is conduαed by reacting hydrazine with the appropriate ketone in an acidic medium, for example, hydrochloric acid/αhanol or acetic acid (for a general review of this reaαion one can consult Robinson "Fischer indole synthesis," Wiley-Interscience, 1982)

In the case of applications of compounds according to the present invention, it should be noted that they can be used as a photochromic material which is dispersed in the superficial part or in the composition of a polymer or mineral matrix They can also be used in solution.

A photochromic solution can be obtained by dissolving the compound in an organic solvent, such as toluene, dichloromethane, tetrahydrofuran or ethanol The solutions obtained are in general colorless and transparent When exposed to sunlight, they developed a strong coloration and their colorless state is restored when they are placed in a zone with less exposure to solar radiation or, in other words, when they are no longer exposed to UV radiation In general, it is sufficient to use a very small concentration of product (on the order of 0 01-5%) to obtain an intense coloration The most intense appUcations are those in which the photochrome is dispersed uniformly within or on the surface of a polymer, copolymer or mixture of polymers A great variety of methods of implementation can be considered Those known to persons skiUed in the art include, for example, diffusion in the (co)polyraer, from a suspension or solution ofthe photochrome, in a silicone oil, in an aliphatic or aromatic hydrocarbon, in a glycol, or from another polymer matrix. The diffusion is routinely conduαed at a temperature of 50-200° C for a duration of 15 min to several hours, depending on the nature ofthe polymer matrix

Another implementation technique consists in mixing the photochrome in a formulation of polymerizable substances, in depositing this mixture on a surface or in a mold and then conducting the polymerization.

These implementation techniques and others are described in the article by CRANO et al. "Spiroxazines and their use in photochromic lenses" published by AppUed

Photochromic Polymer Systems. Published by Blackie and Son Ltd - 1992

According to a variant of the invention, it is also possible to consider grafting the photochromes onto (co)polymers Thus, another object ofthe invention consists of

(co)polymers to which at least one ofthe photochromes described above has been grafted

Examples of preferred polymer materials for the optical applications ofthe photochromic compounds according to the invention include the following produαs:

- polyacrylate or polymethacrylate of alkyl, of cycloalkyl, of aryl or of arylalkyi (mono, di, tri or tetra), optionally halogenated or comprising of at least one ether and/or ester and/or carbonate and/or carbamate and/or thiocarbamate and/or urea and/or amide group(s),

- polystyrene, polycarbonate (e g., bisphenol-A polycarbonate, allyl polycarbonate diethylene glycol, polyepoxy, polyurethane, polythiourethane, polysiloxane, polyacrylonitrile, polyamide, aliphatic or aromatic polyester, vinyl polymers, cellulose acetate, cellulose triacetate, cellulose acetate propionate or polyvinylbutyral,

- copolymers of two or several types of monomer or mixtures of polymers mentioned above, preferably polycarbonate-polyurethane, poly(meth)acrylate- polyurethane, polystyrene-poly(meth)acryiate or polystyrene-polyacrylonitrile, preferably a mixture of polyester or of polycarbonate or of poly(meth)acrylate

The quantity of photochrome used depends on the desired degree of darkening. Usually a quantity of 0.001-20 wt% is used.

The photochromic compounds according to the invention can be used alone or in a mixture with other produαs to form a composition which can be in solid or liquid form, for example, in a solution or in a dispersion, as already indicated above These compositions, which constitute another object ofthe invention, can thus comprise the compounds (I), (F) and (I") ofthe invention and other complementary photochromic compounds which allow the obtention of dark colorations, for example, gray or brown, which are desired by the public in applications such as ophthalmic or sun protection eyewear. These complementary photochromic compounds have an λ^ and an absorbance speαrum in visible such that after association with the compounds of the invention, impart the desired tint to the mixture ofthe aαivated photochromes

The photochrome(s), which can be associated with the compounds ofthe invention, is, are those known to a person skilled in the art and described in the literature, for example, chromenes (U S Patent Nos 3,567,605, 5,238,981 , World Patent No 9,422,850, European Patent No 0,562,91 5), spiropyranes or naphthospyropanes [sic] (U S Patent No 5,238,981 ) and spiroxazines (J C CRANO et al , "Applied

Photochromic Polymer Systems," Publisher Blackie & Son Ltd , 1992, Chapter 2)

These compositions according to the invention can also comprise

- nonphotochromic dyes which allow an adjustment ofthe tint,

- and/or one or more stabilizers, such as, for example, an antioxidant, - and/or one or more anti-UV agents,

- and/or one or more antiradical compounds,

- and or one or more deaαivators of photochemically excited states

These additives can allow an improvement of the durability of said compositions According to another of its aspects pertaining to the application of the photochromic compounds (I), (F) and (I"), the present invention also relates to ophthalmic articles, such as articles of ophthalmic or sun proteαion eyewear, comprising at least one compound according to the invention and/or at least one (co)polymer formed, at least in part, of recurrent units of type (I), (F) or (I") and/or at least one composition comprising the compounds (I), (F) or (I") according to the invention, as defined above, and/or at least one matrix, as defined above, made of an organic polymer material or of a mineral material or of a mineral-organic hybrid material incorporating at least a compound ofthe invention.

In practice, the articles which are most referred to by the present invention are photochromic ophthalmic or sunproteαion lenses, window panes (windows for buildings, for locomotives, automobiles), the optical devices, the decorative articles, the articles for sun protection, the storage of data, etc.

The present invention wiU be understood bαter in Ught ofthe following examples of photochromic synthesis and validation of compounds (I), (F) and (I") which it concerns.

EXAMPLES

Synthesis and properties of photochromic compounds (l )-(4) according to the invention (Examples 1-4)

The formulas of compounds (l)-(4) are given below (see Table I)

Example 1 Synthesis of compound ( 1 )

Step 1

Synthesis of 2-methylcyclohexylphenylamine

In a 100-mL flask, the foUowing mixture is heated at reflux for 30 h 9 3 g aniline, 1 1 2 g 2-methylcyclohexanone and 12 g benzotriazole Then, 200 mL of methanol and 5 g of NaBH ₄ in portions are added to the mixture, which is then heated at reflux for 30 min. The solution is allowed to cool, and 100 mL of water are added to the mixture, which is extraαed with 2 x 100 mL diisopropyl ether The organic phase is recovered, dried over magnesium sulfate and reduced to dryness. In this manner, 7 g of the desired amine are produced.

Step 2.

Synthesis of 1 -(2-methylcyclohexyl)- 1 -phenylhydrazine

The amine from the preceding step (7 g) is suspended in 100 mL of hydrochloric acid (IN), and then the mixture is maintained at 0°C with stirring. An aqueous solution of NaNO ₂ (2 g in 20 mL of water) is then added to the mixture in smaU portions The temperature is then aUowed to rise to the ambient temperature, and the nitroso derivative is extraαed with 2 x 100 mL diisopropyl ether After evaporation ofthe solvent, 8 g of produα are recovered This produα is then added slowly and in small

portions into tetrahydrofuran (80 mL) containing 3 g LiAlH ₄ and, then, the mixture is heated at reflux for 1 h The mixture is subsequently cooled to 0°C, and then the excess of hydride is neutralized with an aqueous soda solution Next, 30 g Na-SO _« are added, and the organic phase is recovered by filtration and reduced to dryness In this manner 7 g ofthe desired hydrazine are produced.

Step 3

Synthesis ofthe 2-mαhylene derivative

In a 100-mL flask, 7 g hydrazine from the preceding step and 3 g 3-methyl-2- butanone in 30 mL ethanol containing 1 drop of acetic acid at 50° C are reaαed Then 5 mL concentrated hydrochloric acid are added, and the mixture is heated at reflux temperature for 10 min The medium is then neutralized with soda and the indole derivative is extraαed with 100 mL dϋsopropyl ether After evaporation of the solvent,

3 g of the desired produα are obtained.

Step 4

Synthesis of spiroxazine ( 1 )

The produα ofthe preceding step (3 g) and 1 8 g 1 -nitroso-2-naphthol are dissolved in 30 mL ethanol, and then the mixture is heated at 70° C for 30 min. The solvent is then evaporated under a vacuum, and the produα is then isolated by chromatography on a sUica column with toluene as eluant. The produα obtained (1 g) is crystaUized in heptane. 450 mg of a sUghtly green produα are isolated. Its structure is confirmed by NMR speαroscopy

Example 2 Synthesis of compound (2)

Step 1

In a 100-mL flask, the foUowing mixture is heated at 120°C for 24 h: 12 g 3,4- dimethylaniline, 1 1 g 2-methylcyclohexanone and 12 g benzotriazole The 2-methylcyclohexyl-2,4-dimethylphenylamine is isolated after reduction, as in step 1 of Example 1 18 g of an oily produα are isolated.

Steps 2, 3 and 4:

These steps are conduαed as before. The spiroxazine (2) is synthesized from 3 5 g ofthe indoline derivative and 2.2 g l-nitroso-2-naphthol in ethanol at 60° C for 2 h. 1 5 g of produα are isolated after chromatography Its structure is confirmed by NMR spectroscopy The latter shows the existence of several isomers, because ofthe position ofthe two methyls on the phenyl ofthe indole (4,5-dimethyl and 5,6-dimethyl derivative) and because ofthe position ofthe nitrogen on the ring (cis and trans with respect to the 2-methyl group).

Example 3 Synthesis of compound (3)

Step I

In a 250-mL flask, equipped with a Dean-Stark separator, the foUowing mixture is heated at reflux: 12 g 3,4-dimethyianiline, 20 g menthone, 14 g benzotriazole and 200 mL toluene. After recovery ofthe theoretical quantity of water ( 16 h), the mixture is reduced to dryness and then dissolved in 200 mL methanol and the produα is reduced with NaBH ₄ , as above. 25 g of an oϋy produα are isolated.

Steps 2, 3 and 4:

These steps were conduαed as before, the spiroxazine (3) is synthesized from 5 g ofthe indoline derivative and 3 5 g 1 -n roso-2-naphthol in 60 mL ethanol at 50° C for 1 h. 2 g of produα are isolated after chromatography Its structure is confirmed by

NMR spectroscopy.

Example 4 Synthesis of compound (4)

This spiroxazine (4) is synthesized from 6 g ofthe indoline derivative of Example

3 and 4 g l-nitroso-7-hydroxy-2-naphthol in the ethanol at 60° C for 1 h. The intermediate produα is then methylated with dimethyl sulfate in acetone in the presence of potassium carbonate. 2.2 g of produα are isolated after chromatography. Its structure is confirmed by NMR speαroscopy.

APPLICATIONS

Example 5: Incorporation of compounds (1) through (4) in a polyacrylate

General procedure: 10 mg of each one of compounds ( 1 ) through (4) are dissolved in tetraethoxylated bisphenol A dimαhyl mrthacrylate, marketed under the name DLACRYL 121 by the company AKZO) and also containing 40 mg of 2',2'-azobis(2-methylbutyτonitrile). The solution is then degassed, rendered inert with argon, and then poured in a lens mold made of glass having a diamαer of 8 cm and a thickness of 2 mm. The mold is then placed in an oven at 70° C for 12 h. After removal from the mold, a transparent and rigid lens is obtained. When exposed to solar-type radiation, the glass quickly develops an intense blue coloration and it again becomes colorless in darkness. The photochromic charaαeristics are given in Table I below For comparison the charaαeristics of compounds Cl, C2, C3, C4 and C5 ofthe prior art are also given in Table I below.

TABLE I Legends

- λ^, measured in D121 in a thickness of 2 mm following exposure to a xenon lamp, 60,000 lx, at 22° C,

- TO = initial transmission (unaαivated state) measured at _mt% ,

- TDI 5 = transmission after 15 min of exposure measured at λ„^

- IOD = Induced optical density (Log(T0 TD15)),

- R ⁵ = % of recovery ofthe initial transmission after 5 min of decoloration

[In the table inserted from the original, commas replace decimal points ]

TABLE I

A comparison ofthe properties of Example I and Comparative Examples Cl and C2, on the one hand, and Examples 2 and 3 and Comparative Examples C3-C5, on the other hand, shows that the compounds ofthe prior art with analogous structure but without an asymmetric aliphatic monocyclic group according to the invention, do not possess the advantageous combination ofthe wanted properties. In particular, it is observed that the compounds ofthe invention have a better compromise between low initial coloration and strong induced optical density