478081-98-0

N-[3-(3-Cyanopyrazolo[1,5-a]pyrimidin-5-yl)phenyl]-N-ethyl-acetamide, a principal impurity of zaleplon, is prepared by Suzuki-Miyaura cross coupling reaction of the corresponding boronic acid and/or boronates with 5-chloropyrazolo[1,5-a]pyrimidin-3-carbonitrile (7). Various methods of preparation of both components are described, as well as approaches based on the final modification of the 5-(3-aminophenyl)-pyrazolo[1,5-a]pyrimidine-3- carbonitrile moiety prepared by Suzuki-Miyaura cross coupling. All the prepared compounds were unambiguouesly identified by NMR techniques. Spectral characteristics (IR, UV, MS) of these compounds are also given.

Zaleplon crystalline Forms II, III, IV and V are useful for the treatment of insomnia. These crystalline Forms are described along with processes for making them by crystallization from selected solvents. A regioisomer of zaleplon is useful as a reference

Zaleplon can be separated from a regioisomer impurity by crystallization from selected solvents or by adding an anti-solvent to a solution of zaleplon and the regioisomer. Zaleplon crystalline Forms II, III, IV, and V are useful for the treatment of insom

The present invention provides a process for the production of N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (zaleplon), an active ingredient that is approved for the treatment of insomnia. The process involves reacting N-[3-[3-(dime

The invention relates to a process for the preparation of zaleplon (N-[3(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethyl-acetamide) in the reaction of 3-dimethylamino-1-(3-N-ethyl-N-acetylaminophenyl)-2-propen-1-one with 3-aminopyrazole-4-carbonitril