Synthesis of (<i>S</i>)-3-(<i>N</i>-Methylamino)-1-(2-thienyl)propan-1-ol: Revisiting Eli Lilly's Resolution−Racemization−Recycle Synthesis of Duloxetine for Its Robust Processes
作者:Yoshito Fujima、Masaya Ikunaka、Toru Inoue、Jun Matsumoto
DOI:10.1021/op060118l
日期:2006.9.1
from 2-acetylthiophene (4) in a two-step overall yield of 79%, is resolved into (S)-6 of 93% ee as its diastereomeric salt (8) with (S)-mandelic acid (7) according to Eli Lilly's procedures developed for the resolution−racemization−recycle (RRR) synthesis of duloxetine (2) with some modifications in terms of practicality. On its liberation from 8, (S)-6 undergoes N-demethylative ethyl carbamate formation
由2-乙酰基噻吩(4)制备的(±)-3-(N,N-二甲基氨基)-1-(2-噻吩基)丙-1-醇(6)以两步法总收率为79%拆分成(小号) - 6 93%ee的作为其非对映体盐(8)与(小号) -扁桃酸(7根据Eli Lilly公司的程序度洛西汀的分辨率外消旋化的再循环(RRR)合成开发)(2)在实用性方面进行了一些修改。在从8释放时,(S)-6经历N在两个不连续但连续的步骤中分别形成8-脱甲基氨基甲酸乙酯:(1)碳酸O-乙酯和(2)氨基甲酸乙酯的形成,同时伴随N-甲基的损失,总收率为87%。然后进行碱水解,可得到100%ee的(S)-3-(N-甲基氨基)-1-(2-噻吩基)丙-1-醇(1),据称是度洛西汀(2)的倒数第二个前体,产率为75%。从乙基环己烷中重结晶一次后。在这样开发的整个过程中,PhMe成功地替代了t -BuOMe,t -BuOMe是一种溶剂,已在礼来的原始RRR合成2中得到了很好的应用。