Abstract Four novel thiourea derivatives containing a thiazole moiety were synthesized and characterized by IR, 1 H and 13 C NMR, mass spectrometry and elemental analysis. The crystal structure of 1a was determined from single crystal X-ray diffraction data. It crystallizes in monoclinic space group P2 1/n with unit cell dimensions a= 11.7752 (6) Å, b= 3.8677 (2) Å, c= 27.4126 (13) Å and β= 92.734 (5) Å. There is a strong intramolecular hydrogen bond ...