REACTIVITY OF P-PHENYL SUBSTITUTED BETA-ENAMINO COMPOUNDS USING K-10 ULTRASOUND .1. SYNTHESIS OF PYRAZOLES AND PYRAZOLINONES/

The reactivity of the beta-enamino ketones, 3-amino-1-(p-phenyl-substi tuted)-2-buten-1-ones 1a-d and beta-enamino esters, ethyl 3-amino-3-(p -phenyl-substituted)-2-propen 5a-d was systematically studied when all owed to react with hydrazine and methylhydrazine under solid support K -10/ultrasound conditions and in homogeneous media (reflux in ethanol or dichloromethane). The products were pyrazoles 2a-d, N-methylpyrazol es 3a-d, 4a-d and N-methylpyrazolinones 6a-c and 7a-c. The regiochemis try of the cyclization reactions showed dependence upon the reaction c onditions employed as well as upon the substituent in the aromatic rin g.