Efficient Synthesis of (R)-6 Benzyloxycarbonylamino-1-methyl-4(3-methylbenzyl)hexahydro-1,4-diazepine. I.
作者:Hiroshi HARADA、Toshiya MORIE、Shiro KATO
DOI:10.1248/cpb.46.1160
日期:——
An efficient and practical method for large scale synthesis of (R)-6-benzyloxycarbonylamino-1-methyl-4-(3-methylbenzyl)hexahydro-1, 4-diazepine (R-3), which is a key intermediate in the synthesis of DAT-582, a potent and selective serotonin-3 receptor antagonist, is described. The precursor of R-3, the (S)-2, 3-diaminopropylaminoacetate S-5, was obtained from the chiral triaminopropane derivative R-19. Nucleophilic reaction of the chiral mesylate R-11 with 3-methylbenzylamine gave the racemic 2, 3-diaminopropylaminoacetate (±)-5 via the achiral azetidinium cation 12, while the reaction of the N-protected mesylate R-14 produced the desired triamine S-15 but in poor yield.However, reaction of the N-protected mesylate S-18 with a large excess of methylamine proceeded smoothly to afford R-19 in good yield. S-5 was converted into R-3 with >99% enantiomeric excess using an intramolecular reductive cyclization method.
本文介绍了一种高效实用的方法,用于大规模合成(R)-6-苄氧羰基氨基-1-甲基-4-(3-甲基苄基)六氢-1,4-二氮杂卓(R-3),它是合成强效选择性 5-羟色胺-3 受体拮抗剂 DAT-582 的关键中间体。R-3 的前体--(S)-2, 3-二氨基丙基氨基乙酸酯 S-5 是从手性三氨基丙烷衍生物 R-19 中获得的。手性甲磺酸盐 R-11 与 3-甲基苄胺发生亲核反应,通过非手性的氮杂环丁烷阳离子 12 得到外消旋的 2,3-二氨基丙基氨基乙酸盐 (±)-5,而 N 保护的甲磺酸盐 R-14 反应生成了所需的三胺 S-15,但收率很低。利用分子内还原环化方法,S-5 被转化为 R-3,对映体过量率大于 99%。