Microwave-Assisted Synthesis of Novel 2,4-Dihydro-5-[4-(trifluoromethyl)phenyl]-3H-1,2,4-triazol-3-ones and Potentiometric Determination of Their pKa in Nonaqueous Solvents
The novel 4‐amino‐ or 4‐aryl‐substituted 2,4‐dihydro‐5‐[(4‐trifluoromethyl)phenyl]‐3H‐1,2,4‐triazol‐3‐ones 3a–3g were synthesized by reaction of N‐(ethoxycarbonyl)‐4‐(trifluoromethyl)benzenehydrazonic acid ethyl ester (2) and primary amines or hydrazine by microwave irradiation. Compounds 3a–3g were potentiometrically titrated with tetrabutylammonium hydroxide (Bu4NOH) in four nonaqueous solvents,