A convenient, rapid, and highly selective method for synthesis of new pyrazolo[1,5-a]pyrimidines via the reaction of enaminones and 5-amino-1H-pyrazoles under microwave irradiation

✍ Scribed by Li Ming; Wang Shuwen; Wen Lirong; Yang Huazheng; Zhang Xiuli

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2005
• Tongue: English
• Weight: 76 KB
• Volume: 42
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570420526

✦ Synopsis

Abstract

Twelve new 7‐aryl‐3‐cyanopyrazolo[1,5‐a]pyrimidines (3a‐f) and ethyl 7‐arylpyrazolo[1,5‐a]pyrimidine‐3‐carboxylates (3g‐l) have been conveniently synthesized by the reaction of enaminones with 5‐amino‐1__H__‐pyrazoles in good yields under microwave irradiation. With one substituded enaminone, only one regioiso‐mer was obtained. The structures of new compounds were fully confirmed by elemental analysis, ir, ^1^H nmr and X‐ray diffraction (XRD) analysis. A plausible reaction mechanism for the synthesis of title compounds is presented. The antifungal activities of some compounds are also reported.