Thiazole analogs of benzomorphans. II. Synthesis of novel thiazolo(5,4-f)morphans.
作者:KIMIO KATSUURA、KEIICHI YAMAGUCHI、SHINICHIRO SAKAI、KEMMOTSU MITSUHASHI
DOI:10.1248/cpb.31.1518
日期:——
Cyanomethylation of 4, 5, 6, 7-tetrahydro-6, 6-dimethyl-7-oxobenzothiazole (VII), which was prepared from 4, 4-dimethyl-1, 3-cyclohexanedione (I) in several steps, afforded the cyano alcohol (VIII). Compound VIII was treated with lithium aluminum hydride and the resulting amino alcohol (IX) was converted into 7-(2-aminoethyl)-4, 7-dihydro-6, 7-dimethylbenzothiazole (XI) by Wagner-Meerwein rearrangement. Reaction of XI with bromine gave the salt (XII). Treatment of XII with potassium carbonate produced the bridged aziridine (XIII), which was cleaved to the thiazolo [5, 4-f] morphan (4, 5, 6, 7, 8, 9-hexahydro-5, 9-methanothiazolo [4, 5-d] azocine) derivative (XVI) by the action of benzoyl bromide. Dehydrobromination followed by hydrolysis of the benzoyl group led XVI to 5-methyl-9-methylenethiazolo [5, 4-f] morphan (XVIII). Stereospecific hydrogenation of XVIII yielded the 9α-methyl isomer (XIX), whose N-methylation by the Eschweiler-Clarke method completed the synthesis of the desired thiazolo [5, 4-f] morphan (XX). The molecular structure of the oxalate of XIX was established by X-ray analysis.
以几步从4,4-二甲基-1,3-环己二酮(I)制得的4,5,6,7-四氢-6,6-二甲基-7-氧代苯并噻唑(VII),经过氰甲基化反应得到氰醇(VIII)。化合物 VIII用氢化铝锂处理,所生成的氨基醇(IX)经过Wagner-Meerwein重排转变成7-(2-氨基乙基)-4,7-二氢-6,7-二甲基苯并噻唑(XI)。化合物 XI与溴反应生成盐(XII),用碳酸钾处理化合物 XII,即生成桥式氮杂环丙烷(XII),再由苯甲酰溴作用得到噻唑并[5,4-f]吗啡烷(4,5,6,7,8,9-六氢-5,9-亚甲基噻唑并[4,5-d]氮杂萘)衍生物(XVI)。通过脱溴再用酸水解去苯甲酰基把 XVI转化成5-甲基-9-亚甲基噻唑并[5,4-f]吗啡烷(XVIII)。把 XVIII进行立体选择性氢化,得到9α-甲基异构体(XIX),再经过Eschweiler-Clarke反应将 XIX进行 N-甲基化就完成了所需要的噻唑并[5,4-f]吗啡烷(XX)的全合成。用 X 衍射分析确定了 XIX 的草酸盐的分子结构。