Reaction of 2-Oxoindolin-3-Ylidene Derivatives with Heterocyclic Enamines. A Convenient One-Pot Synthesis of Pyrimido [5,4:5',6']Pyrido[2,3-b]-Indole-2,4-Dione and Spiro Indolin-2-One-3,5'-Pyrido [2,3-d] Pyrimidines

Abstract

The reaction of 6-aminouracils 2a, b with 2-oxoindolin-3-ylideneacetophenones 1a-h afforded Pyrimido[5,4:5', 6'] pyrido-[2, 3-b] indole- 2,4-diones 3 a-k via a regiospecific Michael addition, followed by cyclization. Alternatively, the reaction of 2a with 2-oxoindolin-3-ylidenemalononitriles 6a, b gave rise to regiospecific formation of spiro indolin-2-one-3, 5'-pyrido[2,3-d]pyrimidines 7a,b.