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Microwave‐Assisted Synthesis of Novel 2,4‐Dihydro‐5‐[4‐(trifluoromethyl)phenyl]‐3 H ‐1,2,4‐triazol‐3‐ones and Potentiometric Determination of Their p K a in Nonaqueous Solvents
Author(s) -
Özil Musa,
İslamoğlu Fatih,
Menteşe Emre,
Kahveci Bahittin
Publication year - 2010
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.201000002
Subject(s) - chemistry , trifluoromethyl , hydrazine (antidepressant) , potentiometric titration , tetrabutylammonium hydroxide , dimethylformamide , medicinal chemistry , microwave irradiation , aryl , hydroxide , organic chemistry , catalysis , ion , chromatography , alkyl , solvent
The novel 4‐amino‐ or 4‐aryl‐substituted 2,4‐dihydro‐5‐[(4‐trifluoromethyl)phenyl]‐3 H ‐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 (Bu 4 NOH) in four nonaqueous solvents, i.e. , i PrOH, t BuOH, MeCN, and N,N ‐dimethylformamide (DMF). Also half‐neutralization potential values and the corresponding p K a values were determined in all cases.