Various amides, including some with bulky substituents, are prepared in good yields from free carboxylic acids and amines under mild conditions by a one-step method using new condensing agents 2-halo-2,3-dihydro-1,3,4,2-oxadiazaphospholes, especially 5-methyl-2-chloro-3-phenyl-2,3-dihydro-1,3,4,2-oxadiazaphosphole.
使用新型
缩合剂2-卤代-2,3-二氢-1,3,4,2-氧二氮
磷杂(2-halo-2,3-dihydro-1,3,4,2-oxadiazaphospholes),特别是5-甲基-2-
氯-3-苯基-2,3-二氢-1,3,4,2-氧二氮
磷杂(5-methyl-2-chloro-3-phenyl-2,3-dihydro-1,3,4,2-oxadiazaphosphole),通过一步法在温和条件下,可以从游离
羧酸和
胺类以良好产率制备各种酰胺,包括一些带有大体积取代基的酰胺。