Synthesis and Transformations of 2-Substituted Tetrahydro-4 H -benzo[4,5]thieno[2,3-d][1,3]oxazines and 2,3-Disubstituted Hexahydrobenzo[4,5]thieno[2,3-d]pyrimidines
作者:A.-A. S. El-Ahl、M. A. Ismail、F. A. Amer
DOI:10.1080/10426500307943
日期:2003.2.1
have been prepared via succinoylation of ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate 1 , followed by ester hydrolysis, selective esterification, and acetic anhydride induced cyclization of the thiophenecarboxylic acid derivatives 3 , 5 . Reaction of 1 with diethyl malonate gave the malonic acid diamide 7 , which on ester hydrolysis followed by acetic anhydride induced water elimination
3-(4-Oxo-5,6,7,8-四氢-4 H-苯并[4,5]噻吩并[2,3-d][1,3]恶嗪-2-基)丙酸及其乙基通过 2-氨基-4,5,6,7-四氢苯并[b]噻吩-3-羧酸乙酯 1 的琥珀酰化,然后进行酯水解、选择性酯化和乙酸酐诱导的噻吩羧酸环化,制备了酯 6a , b酸衍生物 3 , 5 。1 与丙二酸二乙酯反应得到丙二酸二酰胺 7 ,通过酯水解和乙酸酐诱导的水消除得到 2-取代的 4 H-苯并[4,5]噻吩并[2,3-d][1,3 ]恶嗪衍生物10的收率很高。一系列新的苯并[4,5]噻吩并[2,3-d]嘧啶 11-19 ,其在 2-位带有丙酸取代基和氨基、芳基、氨基糖、通过 6a、b 与水合肼或芳香胺反应,然后用芳香醛、靛红或醛糖处理,制备了 3-位的芳基亚甲基氨基取代基。醛亚胺 18a-d 经历了前所未有的酸催化串联环化-跨环醛挤压成八氢-1 H-苯并[4',5']噻吩并[2'