Synthesis and characterisation a series of N-(3,4-dichlorophenyl)-N′-(2,3 and 4-methylbenzoyl)thiourea derivatives

Three new compounds, N-(3,4-dichlorophenyl)-N′-(2-methylbenzoyl)thiourea (2a), N-(3,4-dichlorophenyl)-N′-(3-methylbenzoyl)thiourea (2b) and N-(3,4-dichlorophenyl)-N′-(4-methylbenzoyl)thiourea (2c) are isomers which have been successfully synthesised and characterised by typical spectroscopic techniques, namely IR and 1H and 13C multi-nuclear magnetic resonance (NMR). The structure of 2a was determined by single crystal X-ray diffraction method and crystallised in the monoclinic system with space group C2/c, adopting configuration of the molecule is trans–cis. The infrared spectra of these compounds showed four significant stretching vibrations of ν(NH), ν(CO), ν(CN) and ν(CS) at 3261–3279 cm−1, 1662–1680 cm−1, 1345–1379 cm−1 and 688–738 cm−1, respectively. The 13C NMR chemical shift for the thiourea moiety appeared at ca. δC 180 ppm.