Patent ID: 7772394
Filing Date: 2010-08-10
Classification: C07D

Abstract:
1. A process for making zaleplon, comprising: i. alkylating 3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-acetamide with ethyl iodide in the presence of an alkali metal hydroxide or alkoxide selected from sodium hydroxide, potassium hydroxide, sodium methoxide, sodium tert-butoxide or potassium tert-butoxide in an aprotic solvent to give N-ethyl-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-acetamide; ii. condensing N-ethyl-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-acetamide and 3-amino-4-cyanopyrazole, wherein the condensing is done in the presence of (a) a water immiscible organic acid, wherein the water immiscible acid used for the condensation reaction is edetic acid, fumaric acid, salicyclic acid or benzoic acid; (b) a cation exchange resin; or (c) a water miscible organic acid in water or in a C-1 to C-4 alcohol or in a mixture of water and a C-1 to C-4 alcohol; and iii. isolating zaleplon from the reaction.