Straightforward and Clean Ultrasound-Promoted Synthesis of 2-(4,5-Dihydro-1H-pyrazol-1-yl)pyrimidines
摘要:
A series of twelve novel 2-(pyrazol-1-yl) pyrimidine derivatives was easily obtained under ultrasonic conditions by the cyclocondensation reaction of 1-carboxamidino-pyrazoles with 4-methoxyvinyl-trifluoromethyl ketones using ethanol as an environment-friendly solvent in the presence of potassium hydroxide. Comparison of the ultrasound-promoted reaction with classical methodology shows that the former is faster and gives better yield. The products were isolated in excellent purity grades without purification by chromatography or recrystalization.
Twenty-two pyrazoline derivatives were synthesized and tested for their human MAO (hMAO) inhibitory activity. Twelve molecules with unsubstituted ring A and substituted ring C (5–16) were found to be potent inhibitors of hMAO-A isoform with SIMAO-A in the order 103 and 104. Ten molecules with unsubstituted ring A and without ring C (21–30), in which eight molecules (21, 23–26, and 28–30) were selective