

A REGIOSELECTIVE SYNTHESIS OF 5-DIFLUOROMETHYL- AND 7-DIFLUOROMETHYL-SUBSTITUTED PYRAZOLO[1,5-a]PYRIMIDINES

Abstract
The cyclocondensation of 3,4-substituted 5-aminopyrazoles with unsymmetrical 1,3-dicarbonyl compounds containing the difluoromethyl group in acetic acid led to 7-difluoromethylpyrazolo[1,5-a]pyrimidines, whereas 5-difluoromethylpyrazolo[1,5-a]pyrimidine derivatives were predominantly formed in trifluoroacetic acid.
Keywords
5-aminopyrazoles; 1-cyclopropyl-4,4-difluoro-1,3-butanedione; 5-difluoromethylpyrazolo[1,5-a]pyrimidines; 7-difluoromethylpyrazolo[1,5-a]pyrimidines; 4,4-difluoro-1-phenyl-1,3-butanedione; trifluoroacetic acid; condensation.
Latvian Institute of Organic Synthesis - Aizkraukles iela, 21, Riga, LV-1006, Latvia - hgs@osi.lv