| abstract |
NEW MATERIAL: The compd. of formula I [R 1 is (substd.) 1-12C alkyl, carboxyl, 1-12C alkoxycarbonyl, carbamoyl or the like; R 2 to R 5 are each, (substd.) 1-12C alkyl, provided that, when R 3 is H, the position of the ring of the substituent CH 2 -R 1 and R 4 in one or both azulene rings may be exchanged with each within the one azulene ring; when R 3 is methyl, ethyl or the like, R 1 is H]. n EXAMPLE: A quaiazulenepropionic acid isopropyl ester squaric acid dye. n USE: An optical recording medium. n PROCESS: The azulene deriv. of formula II and the squaric acid of formula III are brought into reaction. n COPYRIGHT: (C)1989,JPO |