Synthesis and characterization of new (E)-N''-(substituted benzylidene)-2-(3-(2-methyl)-4-oxo-3,4-dihydroquinazolin-2-ylthio)acetohydrazides

A small library of new azomethine derivatives of 3-aryl-2-thioxo-2,3-dihydroquinazolin-4(1H)-ones was synthesized. The key intermediates 2-thioxo-quinazolinones (3a--e), obtained in 2 steps from the corresponding anilines, were treated with methyl chloroacetate to afford S-substituted esters (4a,d), which were then converted into corresponding acetohydrazides (5a,d). Further, acetohydrazide (5d) was converted to the azomethines derivatives (6a--k) by reacting with a number of suitably substituted benzaldehydes. FTIR, 1H NMR, 13C NMR, GC-MS, and elemental analyses were used to confirm the assigned structures of the synthesized compounds. Further, compounds 3a, 5, and 6j were also confirmed by X-ray diffraction data.