Synthesis, X-Ray Crystal Structure and Spectroscopic Properties of 1,2,3,4-Tetrahydro-2-(thenyl)-3-(N-thenylidine)-4-oxoquinazoline

The Schiff base formed between anthraniloyl hydrazide and thiophen-2-aldehyde is synthesized. Reaction of this Schiff base with VOSO4 in methanol at room temperature does not yield the expected vanadium complex; instead, the Schiff base is transformed to 1,2,3,4-tetrahydro2-(thenyl)-3-(N-thenylidine)-4-oxoquinazoline, which has been characterized by elemental analyses and by LC-MS, i.r., n.m.r. and electronic spectroscopies. The X-ray crystal structure of the quinazoline product is reported. The compound crystallizes with monoclinic (P2(1)/n) space group, and the cell parameters are: a = 5.9442(7) angstrom, b = 13.6357(15) angstrom, c = 19.455(2) angstrom, beta = 90.499(2)degrees. The oxo-quinazoline product is found to be luminescent when excited at its lowest energy transition.