摘要:
A convenient method for the synthesis of 4-[2-(benzo[b]furan-2-yl)phenyloxy]butyric acid derivatives with a carbamoyl group at the 5 or 6 position of the benzofuran ring showing potent 5 alpha-reductase inhibitory activities was developed. Oxazolin-2-ylbenzofuran derivatives were treated with tert-BuLi followed by tri(n-butyl)tin chloride, to give 2-tri(1-butyl)stannylbenzofuran derivatives. A palladium-catalyzed cross-coupling reaction of these benzofuran derivatives with tert-butyl 4-(2-iodophenyloxy)butyrate afforded the 2-phenyl benzofuran compounds in good yields.