synthesis and non-aqueous medium titrations of some new 4-benzylidenamino-4,5-dihydro-1h-1,2,4-triazol-5-one derivatives合成和非水滴定介质的一些新的4-benzylidenamino-4,5-dihydro-1h-1,2,4-triazol-5-one衍生品.pdf

Molecules 2005, 10, 961-970 molecules ISSN 1420-3049 Synthesis and Non-Aqueous Medium Titrations of Some New 4-Benzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives 1 * 2 1 1 3 Haydar Yüksek , , Osman Üçüncü , Muzaffer Alkan , Zafer Ocak and Şule Bahçeci 1 Education Faculty, Kafkas University, 36100 Kars, Turkey; Fax (+90)-474-2121185. 2 Department of Chemistry, Kafkas University, 36100 Kars, Turkey. 3 Fatih Education Faculty, Karadeniz Technical University, 61080 Trabzon, Turkey. *Author to whom correspondence should be addressed; e-mail: hyuksek98@ Received: 26 August 2004; in revised form: 9 April 2005 / Accepted: 10 April 2005 / Published: 31 August 2005 Abstract: The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5- dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5- dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described. The acetylation and methylation reactions of the compounds 3 giving compounds of type 4 and 5, respectively, were investigated. The newly synthesized compounds were characterized using elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 3 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcoh