Synthesis And X-Ray Crystallography Study Of Methyl-2-(3Benzoylthioureido)Acetate And Ethyl-2-(3Benzoylthioureido)Acetate Ibrahim N. Hassan, Bohari M. Yamin & Mohammad B. Kassim* School of Chemical Sciences & Food Technology Faculty Science & Technology, Universiti Kebangsaan Malaysia 43000 Bangi, Selangor, Malaysia *Email: mbkassim@ukm.my ABSTRACT Two novel benzoylthiourea derivatives of glycine namely, methyl-2-(3- benzoylthioureido)acetate (I) and ethyl-2-(3-benzoylthioureido)acetate (II), were successfully synthesized from 2-(3benzoylthioureido)ethanoic acid in methanol and ethanol, in the presence of LaCl3, respectively. The compounds were characterized by CHNS elemental micro-analysis, infrared and nuclear magnetic resonance spectroscopies. In addition, the X-ray crystallography structures of I and II were determined. Both compounds crystallized in monoclinic crystal system with space group of P21/c. The cell parameters for I and II are a = 14.564(5) Å, b = 4.9746(16)Å, c = 16.883(5)Å and Z = 4 and a = 11.908(4) Å, b = 7.795(3) Å, c = 14.024(5)Å and Z= 4, respectively. The molecules retains the cis-trans configuration with respect to the position of the glycine moiety and benzoyl groups against the S atom across the C-N bonds.