Synthesis, Structure, and Conformational Analysis of N-(2,4-Dichlorophenyl)-2-[6-methyl-2,4-dioxo-3-(thietan-3-yl)-1,2,3,4-tetrahydropyrimidine-1-yl]acetamide

The reaction of 6-methyluracil with 2-chloromethyltiiran affords 6-methyl-3-(thietan-3-yl)uracil. Its subsequent reaction with N-(2,6-dichlorophenyl)-2-chloroaceta­mide resulted in N-(2,4-dichlorophenyl)-2-[6-methyl-2,4-dioxo-3-(thietan-3-yl)-1,2,3,4-tetrahydropyrimidin-1-yl]acetamide, proved by X-ray analysis, NMR and IR spectroscopy. Computer modeling at the PBE/3ζ, PBE/cc-pVDZ and PBE/SV(P) levels showed that its conformational behavior is determined by internal rotation of the thietanyl group both in the gas phase and in chloroform or dimethyl sulfoxide solutions.