Open AccessSalicylic aldehyde-n(4)-(4-ethoxyanilinyl) thiosemicarbazone: optimization of synthesis by surface response and structural characteristics
Author(s) -
Trần Bữu Đăng,
Le Chi Hien Dat,
Vu Tuan Huy,
Nguyễn Minh Phương,
Đình Phú Vũ
Publication year - 2019
Publication title -
tạp chí khoa học đại học sư phạm thành phố hồ chí minh
Language(s) - English
Resource type - Journals
ISSN - 2734-9918
DOI - 10.54607/hcmue.js.16.6.2514(2019
Subject(s) - semicarbazone , salicylic acid , aldehyde , chemistry , acetic acid , yield (engineering) , condensation reaction , heteronuclear single quantum coherence spectroscopy , nuclear chemistry , proton nmr , catalysis , stereochemistry , medicinal chemistry , organic chemistry , two dimensional nuclear magnetic resonance spectroscopy , biochemistry , materials science , metallurgy
Salicylic aldehyde-N(4)-(4-ethoxyanilinyl)thiosemicarbazone (H2L) was synthesized by condensation between salicylic aldehyde (SA) and N(4)-(4-ethoxyanilinyl)thiosemicarbazide (TSCZ) in presence of glacial acetic acid as a homogeneous catalyst in ethanol. As a result of analysis by the surface response based on Box – Hunter model with the confidence level of 95%, the expectable yield reached the highest point (around 68%) at 80oC for 10 minutes when approximately 1 mole of SA reacted to equivalently 1 mole of TSCZ. The structure of H2L was solved by IR, UV-Vis, 1H and 13C NMR, HSQC, HMBC and HRMS, which indicated that the thioketone is the predominant form of H2L in the solid phase. The UV-Vis data in variety of pH showed that H2L was assigned to be a diacid with pKa1 = 8.8 and pKa2 = 13.6.