Synthesis of bioactive quinazolin-4(3H)-one derivatives via microwave activation tailored by phase-transfer catalysis.

A series of nine new 2,3-disubstituted 4(3H)-quinazolin-4-one derivatives was furnished starting from the 2-propyl-4(3H)-quinazo-line-4-one (2). The reinvestigation of the key starting quinazolinone 2 was performed under microwave irradiation (MW) and solvent-free conditions. Combination of MW and phase-transfer catalysis using tetrabutylammonium benzoate (TBAB) as a novel neutral ionic catalyst was used for carrying out N-alkylation and condensation reactions of compound 2 as a simple, efficient and eco-friendly technique.

Efficient 1,3,4-Thiadiazole-4,5-dihydropyridazin-3(2H)-ones as Antimicrobial Agents.

A set of novel series of 1,3,4-thiadiazolyl-sulfanyl-4,5-dihydropyridazin-3(2H)-ones with anticipated antimicrobial activity has been synthesized. The synthetic protocol of the targeted compounds was accomplished by treating β-aroylacrylic acid 1 with 5-amino-1,3,4-thiadiazole-2-thiol (2) to afford the thia-Michael adduct 3. Afterwards, the obtained thia-Michael adduct 3 was cyclized to 4,5-dihydropyridazin-3(2H)-ones 4a-d and the non-cyclized product hydrazone 5 by using different hydrazines.