Process for purifying N-3-(3-cyanopyrazolo1,5-apyrimidin-7-yl)phenyl-N-ethylacetamide(zaleplon) and crystalline forms of zaleplon accessible with the process

摘要

Provided are novel Zaleplon crystalline Forms II, III, IV and V, which are useful for the treatment of insomnia. Also provided are processes for making Forms I, II, and V using precipitation methods.