作者:Gunther Schmidt、Martin H. Bolli、Cyrille Lescop、Stefan Abele
DOI:10.1021/acs.oprd.6b00210
日期:2016.9.16
A practical synthesis of S1P receptor 1 agonist ACT-334441 (1) through late-stage convergent coupling of two key intermediates is described. The first intermediate is 2-cyclopentyl-6-methoxyisonicotinic acid whose skeleton was built from 1-cyclopentylethanone, ethyl oxalate, and cyanoacetate in a Guareschi–Thorpe reaction in 42% yield over five steps. The second, chiral intermediate, is a phenol ether
描述了通过两个关键中间体的后期收敛偶联,实际合成S1P受体1激动剂ACT-334441(1)。第一个中间体是2-环戊基-6-甲氧基异烟酸,其骨架是由1-环戊烯酮,草酸乙酯和氰基乙酸酯在Guareschi-Thorpe反应中构建的,分5步产率为42%。第二种手性中间体是衍生自对映体纯的(R)-异亚丙基甘油((R一锅缩反应)和3-乙基-4-羟基-5-甲基苄腈,一锅反应的收率为71%。整个序列需要18个化学步骤和10个分离的中间体。所有原料都很便宜,而且容易获得大批量,反应条件与标准的中试设备相匹配,并且该路线可重复提供3–20 kg的1,具有极高的纯度和临床研究产量。