Mono-, bis- and tris-indolyl-substituted furanones useful as color formers, particularly in carbonless duplicating and thermal marking systems, which are prepared respectively by: the interaction of an indole with mucochloric acid; the interaction of an indole with a 4-mono(indolyl-substituted 4-oxo-2-butenoic acid; and by the interaction of an indole with a 2,4-bis(indolyl)-substituted 4-oxobutanoic acid or with a 3,5-bis(indolyl)-substituted furanone.
一种用作颜色形成剂的单-, 双- 和三-
吲哚取代
呋喃酮,特别适用于无碳复写和热标记系统,分别通过以下方法制备:
吲哚与黏
氯酸的相互作用;
吲哚与4-单(
吲哚取代)4-氧代-
2-丁烯酸的相互作用;以及
吲哚与2,4-双(
吲哚取代)4-氧代
丁酸或3,5-双(
吲哚取代)
呋喃酮的相互作用。