Letrozole production process

US7538230B2 · kind B2 · utility

Assignee

• Chemagis Ltd. · IL

Inventors

• Oded Friedman · Haifa, IL
• Boris Freger · Beer Sheva, IL
• Olga Etlin · Beer Sheva, IL
• Julia Ditkovitch · Beer Sheva, IL
• Edna Danon · Meitar, IL
• Yana Seryi · Beer Sheva, IL
• Guy Davidi · Even Yehuda, IL
• Oded Arad · Rehovot, IL
• Joseph Kaspi · Givatayim, IL

Key dates

• Filing date: Nov 14, 2005
• Grant date: May 26, 2009
• Expiry date: Apr 20, 2027

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D249/08
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Provided is a method for preparing letrozole, which includes reacting an activated bis-(4-cyanophenyl)-methane with a triazole to produce letrozole, and, optionally, purifying the letrozole. Also provided are highly pure letrozole, and a method of purifying letrozole, which method includes precipitating letrozole, e.g., by selective precipitation from a reaction mixture and/or by subjecting the letrozole to one or more crystallizations.