This invention is concerned with a new and improved process for the large scale production of 4-\x9b6-(hexylcarbamoyloxy)hexylcarbainoyloxy!-piperidine-1-carboxylic acid 4-phenoxyphenyl ester, disclosed in European Patent Application 0 635 501 A1, published Jan. 25, 1995, a compound that inhibits cholesterol ester hydrolase (CEH) and acylcoenzyme A cholesterol acyltransferase (ACAT). In the invention process, 1-benzyl-4-hydroxypiperidine or 1-methyl-4-hydroxypiperidine is reacted with a carbonylating reagent such as carbonyldiimidazole (CDI) and 6-aminohexanol forming the intermediate 1-benzyl (or methyl)-4-(6-hydroxyhexylcarbamoyloxy)piperidine. Reaction of this intermediate with CDI and hexylamine gives the corresponding 1-benzyl (or methyl)-4-\x9b6-(hexylcarbamoyloxy)-hexylcarbamoyloxy!piperidine. The N-benzyl or methyl group is concomitantly removed and replaced with the 4-phenoxyphenyloxycarbonyl group using 4-phenoxyphenyl chloroformate. The process can be carried out from starting material to final product without isolation of intermediates, without changing the solvent, and the yield and purity of the final product are still more than satisfactory. This modification of the present process is clearly less labor and time intensive than the synthetic route presented in EP 0 635 501 A1.
本发明涉及一种新的和改进的大规模生产4-(己基
氨基羰氧)己基
氨基羰酰氧基!-
哌啶-1-羧酸4-苯氧基苯酯的过程,该化合物抑制
胆固醇酯
水解酶(CEH)和酰
辅酶A胆固醇酰基转移酶(ACAT),并在1995年1月25日公布的欧洲专利申请0 635 501 A1中披露。在这种发明过程中,
1-苄基-4-羟基哌啶或1-甲基-
4-羟基哌啶与羰基化试剂(如羰基二
咪唑(
CDI))和6-
氨基
己醇反应,形成中间体1-苄基(或甲基)-4-(6-羟基己
氨基羰酰氧基)
哌啶。将该中间体与
CDI和
己胺反应,得到相应的1-苄基(或甲基)-4-(己基
氨基羰氧)-己基
氨基羰酰氧基!
哌啶。N-苄基或甲基基团同时被去除,并用4-苯氧基苯酰
氯酸酯替换为4-苯氧基苯氧羰基基团。这个过程可以在不分离中间体的情况下,不改变溶剂,从起始物质到最终产物进行。最终产物的收率和纯度仍然是令人满意的。这种改进的方法显然比EP 0 635 501 A1中提出的合成路线更少劳动和时间。