Synthesis of pyrazolo[1,5‐<i>a</i>]‐, 1,2,4‐triazolo[1,5‐<i>a</i>]‐ and imidazo[1,2‐<i>a</i>]pyrimidines related to zaleplon, a new drug for the treatment of insomnia

Abstract

Abstract This paper describes the preparation of some pyrazolo[1,5‐ a ]‐, 1,2,4‐triazolo[1,5‐ a ]‐ and imidazo[1,2‐ a ]‐pyrimidines substituted on the pyrimidine moiety by a 4‐[( N ‐acetyl‐ N ‐ethyl)amino]phenyl group. A new synthesis of related benzo[ h ]pyrazolo[1,5‐ a ]‐, benzo[ h ]pyrazolo[5,1‐ b ]‐ and benzo[ h ]1,2,4‐triazolo[1,5‐ a ]‐quinazolines is also reported.