[EN] NOVEL METHOD FOR PREPARATION OF ATOVAQUONE<br/>[FR] NOUVEAU PROCÉDÉ DE PRÉPARATION D'ATOVAQUONE
申请人:LUPIN LTD
公开号:WO2012153162A1
公开(公告)日:2012-11-15
Provided is a process of preparation of 2-[trans,-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy- 1,4-naphthoquinone, i.e. Atovaquone [I] which is cost effective, green, and eco-friendly process, without separation of any diastereomers or geometric isomers of intermediates obtained during the reactions. Also provided is separation of 'cis' and 'trans ' isomer of intermediates VI, VII and VIII through selective crystallization in an appropriate solvent. A method for converting 2-[cis,-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-1,4-naphthoquinone to 2-[trans-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-l,4-naphthoquinone in presence of Lewis/ Bronsted acid is also provided. A process for preparation of compound 2-(4-(4- chlorophenyl)- 1 -hydroxy cyclohexyl)-3,4-dihydronaphthalen- 1 (2H)-one [IV] comprising condensation of (1,2-dihydronaphthalen-4-yloxy)trimethylsilane [II] with 4-(4- chlorophenyl)cyclohexanone [III] in presence of Lewis acid in organic solvent. The invention also encompasses a highly efficient and atomeconomic process for synthesis of compound [III] i.e. 4-(4-chlorophenyl)cyclohexanone as well as a process for synthesis of 2-[cis-4-(4'- chlorophenyl)cyclohexyl]-3-hydroxy-l,4-naphthoquinone. Further provided is a process for isomerization of cis- Atovaquone i.e. 2-[cis-4-(4'-chlorophenyl)cyclohexyl]-3-hydroxy-l,4- naphthoquinone to tnms-Atovaquone i.e. 2-[trans-4-(4'-chlorophenyl)cyclohexyl]-3- hydroxy- 1,4-naphthoquinone in presence of Lewis acid.
提供了一种制备2-[反式,-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌,即阿托喹酮[I]的过程,这是一种具有成本效益、绿色、环保的过程,无需分离在反应过程中获得的中间体的对映异构体或几何异构体。还提供了通过在适当溶剂中选择性结晶来分离中间体VI、VII和VIII的'顺式'和'反式'异构体的方法。还提供了一种在路易斯/布朗斯特酸的存在的条件下将2-[顺式,-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌转化为2-[反式-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌的方法。还提供了一种制备化合物2-(4-(4-氯苯基)-1-羟基环己基)-3,4-二氢萘-1(2H)-酮[IV]的过程,包括(1,2-二氢萘-4-氧基)三甲基硅烷[II]与4-(4-氯苯基)环己酮[III]在有机溶剂中在路易斯酸的存在的条件下进行缩合。本发明还涵盖了高效且原子经济的合成化合物[III]即4-(4-氯苯基)环己酮的过程以及合成2-[顺式-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌的过程。还提供了一种在路易斯酸的存在的条件下将顺式-阿托喹酮即2-[顺式-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌异构化为反式-阿托喹酮即2-[反式-4-(4'-氯苯基)环己基]-3-羟基-1,4-萘醌的过程。