method of preparation of substances chromogenes from indole and aromatic dicarboxylic acid anhydrides or heteroaromatiques, busnew chromogenes this category, and their use

摘要

1389716 Colour formers derived from indoles CIBA-GEIGY AG 22 Nov 1972 [26 Nov 1971 12 Oct 1972] 53978/72 Heading C4P [Also in Division D2] Colour formers of the formula wherein A is a fused-on, optionally substituted benzene, naphthalene or heterocyclic ring; R 1 and R 1 SP1/SP are each H, aralkyl or optionally substituted C 1-18 alkyl (other than aralkyl), or C 3-18 alkenyl; R 2 and R 2 SP1/SP are each H, C 1-6 alkyl or aryl; and R 3 and R 3 SP1/SP are each H or C 1-6 alkyl or alkoxy, which are novel except when (a) A is a fused-on, unsubstituted benzene ring and R 1 and R 1 SP1/SP are H or (b) R 1 and R 1 SP1/SP are C 1-5 alkyl, are prepared by reacting 2 moles of an appropriate 3-unsubstituted indole or one 1 mole each of two appropriate 3-unsubstituted indoles with at least 1 mole of an appropriate benzene, naphthalene or heterocyclic dicarboxylic acid anhydride, in the presence of a condensation agent, e.g. acetic anhydride. The products have use in pressure-sensitive recording materials, either alone or in admixture with other known products such as crystal violet lactone.