Synthesis of 4-[1-(4-cyano phenyl)-(1,2,4-triazol-

专利名称：Synthesis of 4-[1-(4-cyano phenyl)-(1,2,4-triazol-1-yl)methyl] benzonitrile and 4-[1-(1H-1,2,4-triazol-1-yl)methylenebenzonitrile intermediate

发明人：Srinivas Laxminarayan Pathi,Rajendra

Narayanrao Kankan,Dharmaraj RamachandraRao,Sandip Vasant Chikhalikar

申请号：US12282859申请日：20070319公开号：US08003804B2公开日：20110823

摘要：The present invention relates to a process for the preparation of 4-[1-(4-cyanophenyl)-1-(1,2,4-triazol-1-yl)methyl]benzonitrile (letrozole), substantially free from itsisomeric impurity. The preparation involves reaction of 4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile with 4-fluorobenzonitrile in the presence of an organic solventand a silicon amine. The present invention also relates to a process for the preparation of4-[1-(1H-1,2,4-triazol-1-yl)methylene benzonitrile which involves: (a) the reaction of a 4-halomethyl benzonitrile with 1,2,4-triazole in the presence of cesium carbonate and anorganic solvent to obtain a reaction mass comprising 4-[1-(1,2,4-triazole-1-yl)methyl]benzonitrile of formula II; and (b) precipitation of 4-[1-(1,2,4-triazole-1-yl)methyl]benzonitrile (II) from the reaction mass using a suitable organic solvent.

申请人：Srinivas Laxminarayan Pathi,Rajendra Narayanrao Kankan,DharmarajRamachandra Rao,Sandip Vasant Chikhalikar

地址：Bangalore IN,Mumbai IN,Mumbai IN,Mumbai IN

国籍：IN,IN,IN,IN

代理机构：Conley Rose, P.C.

代理人：Rodney B. Carroll

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