Optically Active Cyclohexene Derivative as a New Antisepsis Agent: An Efficient Synthesis of Ethyl (6R)-6-[N-(2-Chloro-4-fluorophenyl)sulfamoyl]cyclohex-1-ene-1-carboxylate (TAK-242)
作者:Masami Yamada、Takashi Ichikawa、Toru Yamano、Fumio Kikumoto、Yuji Nishikimi、Norikazu Tamura、Tomoyuki Kitazaki
DOI:10.1248/cpb.54.58
日期:——
Two new synthetic methods were established for the efficient synthesis of optically active cyclohexene antisepsis agent, ethyl (6R)-6-[N-(2-chloro-4-fluorophenyl)sulfamoyl]cyclohex-1-ene-1-carboxylate [(R)-1: TAK-242)]. The first method involved recrystallization from methanol of the diastereomeric mixture (6RS,1'R)-7, obtained by esterification of carboxylic acid 3 with (S)-1-(4-nitrophenyl)ethanol
建立了两种新的合成方法,可有效合成光学活性的环己烯防腐剂,乙基(6R)-6- [N-(N-(2-氯-4-氟苯基)氨磺酰基]环己-1-烯-1-羧酸[[R )-1:TAK-242)]。第一种方法涉及通过将羧酸3与(S)-1-(4-硝基苯基)乙醇[(S)-5)酯化获得的非对映混合物(6RS,1'R)-7从甲醇中重结晶为得到具有99%de的所需异构体(6R,1'R)-7,产率为32%。随后的催化氢解和酯化得到具有> 99%ee的(R)-1。第二种方法是使用脂酶PS-D对乙酰氧基甲酯9a(通过3与溴乙酸甲酯的烷基化反应)进行对映选择性水解,从而得到对映体对映异构体(R)-9a,具有优异的对映选择性(> 99%ee)和高收率(48%) )。然后通过在浓硫酸存在下与乙醇进行酯交换而获得所需的(R)-1,而不会损失ee。其中,使用脂肪酶PS-D进行酶促动力学拆分的方法是(R)-1的更有效和实用的制备方法。