PROCESS FOR PREPARATION OF N-[3-(3-CYANOPYRAZOLO [1,5-A]PYRIMIDIN-7-YL)PHENYL]-N-ETHYLACETAMIDE

摘要

An improved process for preparing N-[3-(3-Cyanopyrazolo [1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide, (zaleplon), comprising the steps of reacting N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]phenyl]-N-ethylacetamide with 3-amino-4-cyanopyrazole in a reaction medium comprising (i) water and water-immiscible organic solvents in presence of either organic sulphonic acids or Lewis acids; (ii) aromatic hydrocarbons as solvent in presence of either organic sulphonic acids or Lewis acids; or (iii) water and organic sulphonic acid or Lewis acids.