Photochromic naphthopyran compounds

Details Photochromic naphthopyran compounds Photochromic naphthopyran compounds

1995-11-02

1997-04-22

Ramsuer, Robert W.

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Processes of preparing a desired or intentional composition...

524 99, 524110, 252586, 359290, 523106, 544150, 544 70, 546144, 546196, 548439, 548454, 548525, 548409, 549389, 428913, C07D40502, C07D41302, G02B 523

Patent

active

056230052

DESCRIPTION:

BRIEF SUMMARY
This application is a 371 of PCT/GB94/00628 filed Mar. 25, 1994.
The present invention relates to certain novel photochromic naphthopyran compounds, and to articles and compositions containing them.
Photochromism is a well-known physical phenomenon which 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, Edited by H. Durr and H. Bouas-Laurent, Elsevier 1990.
Naphthopyran compounds as a class of compounds are known to be capable of exhibiting a photochromic effect. For example, U.S. Pat. No. 4,980,089 describes a series of photochromic naphthospiropyran compounds containing a norcamphor group or a tricyclodecane group at the 2-position of the naphthospiropyran ring (This 2-position corresponds to the 3-position of the ring in the numbering system used in the present specification).
A series of novel reversible photochromic naphthopyran compounds carrying an acetoxy group (or analogues thereof) at the 5-position of the naphthopyran ring is described in WO 92/09503.
U.S. Pat. No. 5,106,998 describes a variety of photochromic compounds including various naphthopyran compounds of different structures.
U.S. Pat. No. 5,066,818 describes a group of novel reversible photochromic naphthopyran compounds having at least one ortho-substituted phenyl group at the 3-position of the pyran ring.
We have now found a group of naphthopyran compounds which provide substantially greater induced optical density in their darkened state than other known naphthopyran compounds. The common characteristic of the novel naphthopyran compounds of the present invention is that they carry a substituted amino group in the 6-position of the molecule.
Accordingly, the present invention provides a naphthopyran compound of general formula (I) ##STR2## wherein R.sub.1 represents a group of the formula --NR.sub.2 R.sub.3 wherein each of R.sub.2 and R.sub.3, which may be the same or different, independently represents an alkyl group, or a carbocyclic group, preferably aryl, or a heterocyclic group, or R.sub.2 and R.sub.3 taken together with the nitrogen atom to which they are attached represent a heterocyclic ring having one or more hetero atoms and which may optionally carry at least one substituent selected from alkyl, aryl or heteroaryl groups; independently represents an alkyl, alkenyl, carbocyclic or heterocyclic group, or R.sub.4 and R.sub.5 taken together with the carbon atom to which they are attached form a carbocyclic ring or a heterocyclic ring; and alkoxy, aryl, aryloxy, heteroaryl, halogen, a group of formula R.sub.1 as defined above, azo, imino, amide, carboxylate, ester, cyano, trifluoromethyl or nitro, and in addition R.sub.6 may represent a carbocyclic or heterocyclic ring fused to ring A.
Throughout this specification, unless stated otherwise, the term "alkyl" is to be taken to mean an alkyl group having from 1 to 4 carbon atoms. Similarly, the term "alkoxy" is to be taken to mean an alkoxy group having from 1 to 4 carbon atoms.
Furthermore, in the definitions of R.sub.1, R.sub.4, R.sub.5 and R.sub.6 above, whenever reference has been made to a carbocyclic or heterocyclic ring (or group), unless specified otherwise it is to be understood that such carbocyclic or heterocyclic rings (or groups) may be unsubstituted or may carry one or more substituents chosen from halogen atoms, alkyl, alkoxy, aryl, aryloxy, heteroaryl, amino, a group --NR.sub.2 R.sub.3 as defined above, azo, imino, amide, carboxylate, ester, cyano, trifluoromethyl or nitro groups, or, further, such rings may have one or more further rings which are fused thereto.
For the avoidance of doubt, in the definition of R.sub.1 above, the group --NR.sub.2 R.sub.3 includes within its scope ring systems in which one or more further rings are fused to the heterocyclic ring, and such ring systems may incorporate saturated and/or unsaturated rings. Typical examples of such --NR.sub.2 R.sub.3 groups include a tetrahydroisoquinoline substituent o

REFERENCES:
patent: 4980089 (1990-12-01), Heller
patent: 5066818 (1991-11-01), Gemert et al.
patent: 5106998 (1992-04-01), Tanaka et al.
patent: 5384077 (1995-01-01), Knowles
patent: 5543533 (1996-08-01), Allegrini et al.
Chemical Abstract, vol. 96, No. 28, 1982, Columbus, OH, US; Abstract No. 69027 Abstract (Otsuka Pharmaceuticals.), JP,A,8 149 361, May 2, 1981.

Affiliated with

Also associated with

Rating

Photochromic naphthopyran compounds does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Photochromic naphthopyran compounds, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photochromic naphthopyran compounds will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-342241