Ultrasonic-assisted unusual four-component synthesis of 7-azolylamino-4,5,6,7-tetrahydroazolo[1,5-]pyrimidines.

Four-component reactions of 3-amino-1,2,4-triazole or 5-amino-1-pyrazole-4-carbonitrile with aromatic aldehydes and pyruvic acid or its esters under ultrasonication were studied. Unusual for such a reaction type, a cascade of elementary stages led to the formation of 7-azolylaminotetrahydroazolo[1,5-]pyrimidines.