PURPOSE: To provide new indolinimine dyes with a wide absorption band in the near infrared rays region and a very high sensitivity as a near infrared rays absorbent in an optically recording medium.
CONSTITUTION: A compd. of formula I (wherein R1 is an alkyl or an aryl; R2 is H, an alkyl, etc.; R3 is H, an alkylthio, etc.; R4 is H, an aralkyl, etc.; R5 is an alkyl, an aralkyl, etc.; R6 is H or R5 and R6 form a five- or six-membered ring with N atoms and C atoms bonded therewith; R7 is H, nitro, etc.), e.g. a compd. of formula II is provided. The compd. is obtd. by performing condensation of a compd. of formula III and a compd. of formula IV e.g. at room temp. in the presence of dehydrating solvent by stirring. a compd. of formula III is a new compd. and is obtd. e.g. by performing condensation of a compd. of formula V and malonitrile in the presence of a piperidine catalyst in an inert org. solvent at 20-150°C.
Next Patent: PRODUCTION OF EPSILON TYPE COPPER PHTHALOCYANINE PIGMENT