3a-(4-Chlorophenyl)-1-thioxo-2,3,3a,4-tetrahydroimidazo[1,5-a]quinazolin-5(1H)-one

With the aim to produce new heterocycle molecules, the previously reported 2-(aminomethyl)-2-(4-chlorophenyl)-2,3-dihydroquinazolin-4(1H)-one was converted efficiently by reacting with N,N’-dithiocarbonyldiimidazole (DTCI), to produce the substituted imidazolidine-2-thione moiety inserted in a three fused ring scaffold of the title compound. The molecular composition was confirmed by a high-resolution MS experiment, and its structure was elucidated by 1H, 13CNMR, and IR analyses. The thioacetamide form of the product was supported by density functional theory (DFT)-NMR analysis where 13C chemical shifts of thioacetamide form and of its iminothiol tautomer were calculated in chloroform at the BP86 /Jgauss-TZP2 level of theory. The very good linear correlation between 13C chemical shifts by experiment and by calculation for the NHC=S form confirmed the structure.