Grey coloring photochromic fused pyrans

Details Grey coloring photochromic fused pyrans Grey coloring photochromic fused pyrans

2001-03-16

2002-05-14

Rotman, Alan L. (Department: 1625)

Stock material or miscellaneous articles

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Of quartz or glass

C428S500000, C428S913000, C044S329000, C044S332000, C106S001150, C106S031470, C106S031490, C540S477000, C540S480000, C540S481000, C540S576000, C540S581000, C544S129000, C544S141000, C546S187000, C546S195000, C546S196000, C546S198000, C546S202000, C546S246000, C546S247000, C546S248000

Reexamination Certificate

active

06387512

ABSTRACT:

The present invention relates to new grey colouring photochromic fused pyrans and to their use.
Photochromism is a well-known physical phenomenon that is observed with certain classes of chemical compounds. A detailed discussion of this phenomenon can be found in “Photochromism: Molecules and systems”, Studies in Organic Chemistry 40, Eds. H. Durr and H. Bouas-Laurent, Elsevier, 1990.
The 2H-naphtho[1,2-b]pyran system is known to be capable of exerting a photochromic effect as described, for example, in U.S. Pat. Nos. 3,567,605 and 4,826,977. U.S. Pat. No. 3,567,605 provides an example of a naphtho[1,2-b]pyran which remains coloured at ambient temperatures for several hours, and U.S. Pat. No. 4,826,977 describes a series of yellow/orange colouring 2H-naphtho[1,2-b]pyrans containing a spiro-adamantane group at the 2-position amongst other 2H-[1] benzopyran and isomeric naphthopyran systems. The basic structural unit of the 2H-naphtho[1,2-b]pyran system, in this instance substituted at C-2 with a spiro-adamantane group, is illustrated below.
A range of purple/blue colouring 2(4-aminophenyl)-2-alkyl-2H-naphtho[1,2-b]pyrans have also been described in U.S. Pat. No. 4,818,096.
A series of photochromic 2H-naphtho[1,2-b]pyrans, amongst other 2H[1]benzopyrans and isomeric naphthopyrans, bearing a cyclopropyl group as one of the substituents at the 2-position is described in patent publication WO92/01959. It is also commented that the compound 2-cyclopropyl-2-p-methoxyphenyl-5-methyl-2H-naphtho[1,2-b]pyran and several other analogues are of particular current interest, but no reasons are presented either to substantiate such interest or as to any significance of the 5-methyl group.
It is stated in U.S. Pat. No. 5,066,818 ( 1991 ) that “The compound, 2,2-diphenyl-2H-naphtho[1,2-b]pyran, also colours on exposure to near ultraviolet light at room temperature but does not bleach in a reasonable period of time. Substitution of the phenyl substituents in the meta and para positions have little effect on the rate of bleaching of these compounds.”
The very high optical density of 2,2-diaryl-2H-naphtho[1,2-b]pyrans achieved under irradiation and their slow attendant fade (bleaching) on removal of the source of irradiation relative to the photochromic properties display:ed by the isomeric 3,3-diaryl-3H-naphtho[2,1-b]pyrans has been noted by B. van Gemert et al. (
Mol. Cryst. Liq. Cryst.
1994, 246, 67). The relatively slow attendant fade of the 2,2-diaryl-2H-naphtho[1,2-b]pyrans was rationalised by the absence of steric crowding in the ring opened (coloured) quinoidal/zwitterionic forms. Such steric crowding is thought to be present for the ring opened form of the 3,3-diaryl- 3H-naphtho[2,1-b]pyrans and accounts for their relatively rapid fade.
Pilkington Plc have also commented on the fading of photochromic materials in Research Disclosure {May (1994), No. 36144, p 267}. This disclosure reports that markedly improved rates of fade can be obtained for 2,2-diaryl-2H-naphtho[1,2-b]pyrans bearing substituents at both the 5- and 6- positions compared with 2,2-diaryl-2H-naphtho[1,2-b]pyrans that are unsubstituted at these sites. These substituents are reported to exert steric pressures upon the ring opened (coloured) forms and enhance the ring closure to the uncoloured naphthopyran system. However, these relatively fast fading materials described by Pilkington Plc with substituents at both the 5- and 6- positions are difficult to manufacture, requiring a long multi-stage process which renders them unattractive commercially. Thus the use of two substituents at the 5- and 6- positions to achieve rapid fade in these 2,2-diaryl compounds has the disadvantage of manufacture complexities.
Two more recent U.S. Pat. Nos. 5,458,814 and 5,514,817 describe the synthesis of a range of fast fading intense yellow to red/purple colouring 2,2-diaryl-2H-naphtho[1,2-b]pyrans and phenanthropyrans which either possess a 5-substituent or are 5,6-disubstituted.
Other 5-substituted rapid fading intense colouring photochromic naphtho[1,2-b]pyrans are included in U.S. Pat. No. 5,658,500 (1997). These naphthopyrans, which may also include an aminoaryl group at position 2, can be used in conjunction with other complementary photochromic materials so that together a near neutral grey or brown shade is developed when a lens containing such a mixture is subjected to UV light. Some naphtho[1,2-b]pyrans which may also contain aminoaryl groups at position 2 and are further substituted at position 2,7 and 9 with alkoxy groups have been described in application PCT WO 98/04937. These molecules are attributed with the beneficial properties of higher lambda max values for both of their absorption bands and also have a generally higher induced optical density compared with molecules which do not possess the di-alkoxy substitution pattern.
International patent application WO 95/05382, describes some neutral colouring, typically brown, photochromic heterocyclochromenes in which the hetero ring is fused to either the f- or g-face of the benzopyran unit. No examples or claims pertaining to the h- fused isomers were made. A range of f-fused heterocyclic pyrans has been described in U.S. Pat. No. 5,527,911 (1996). The examples reported in this work all possess unsubstituted phenyl groups at C-2 in the pyran ring and provide orange or red colouring compounds. A subsequent U.S. Pat. No. 5,552,091 (1996) claims f-, g- and h- fused benzofuro-, benzothieno- and indolo- benzopyrans. In all examples, regardless of the mode of ring fusion, C-2 of the pyran ring is substituted with at least one of the following tricyclic moieties: fluorenyl, dibenzofuryl, dibenzothienyl or carbazolyl. No examples of C-2 (monocyclic) diaryl substituents are claimed in this work. An additional PCT, WO 94/20869, also describes f-, g- and h- fusions of benzothiophene and benzofuran to 2,2-diaryl benzopyrans. None of the reported examples pertain to heterocyclic fused 2,2-diaryl benzopyrans in which the pendant aryl groups possess one or more cyclic amino substituents located in the para position.
In International patent application no. PCT/GB98/00904, there are described the synthesis and applications of some neutral colouring (brown or brown/red) photochromic 2,2-diaryl-2H-naphtho[1,2-b]pyrans. The brown or brown/red colouring is obtained by substituting the 2,2-diaryl-2H-naphtho[1,2-b]pyrans in the 7- and/or 9- position with an amino function. The general formula in PCT/GB98/00904 also covers brown or brown/red compounds in which one or both of the 2,2-diaryl groups may be unsubstituted, mono-, di- or poly-substituted and among the possible substitutents are amino, amino C
1
-C
5
alkyl, alkyl C
1
-C
5
amino, dialkyl C
1
-C
5
amino and certain cyclic amino groups. However, there are no specific Examples of such compounds, but only of 2,2-diaryl alkoxy substituted compounds.
We have now found that, surprisingly, photochromic 2,2-diaryl-2H-naphtho[1,2-b]pyrans wherein at least one of the aryl groups is substituted with an amino function, preferably in the para position to the point of attachment to the pyran ring, in addition to amino function substitution at the 7- and/or 9- position, exhibit neutral non-brown, non-brown/red colouring which is quite different from the neutral brown or brown/red described in PCT/GB98/00904. The presence of a 5 substituent in these pyrans may also provide for rapid fading of the colour generated upon irradiation.
The neutral non-brown, non-brown/red colours observed in the photochromic compounds of the invention are typically various shades and hues of grey, blue grey, purple grey, green grey and, on occasion, approach black. They typically result from multiple absorption bands at about 460-520 nm and about 550-650 nm upon irradiation with sunlight or a suitable artificial light source. The bands are often broa

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