2-N-(Acylmethyl)aminochromones were prepared from 2-chlorochromone and
alpha-amino ketones (hydrochloride or ketal derivatives) in ethanol/t
riethylamine. Their treatment with acetic acid/pyrrolidine led to [1]b
enzopyrano[2,3-b]pyrrol-4(1H)-ones, which were subsequently functional
ized in C2 by aromatic electrophilic substitution (acetylation, bromin
ation or nitration). (C) 1997 Elsevier Science Ltd.