Syntheses and Crystal Structures of Benzyl Substituted Thiazolidin-2-cyanamide Derivatives

Reaction of thiazolidin-2-cyanamide and substituted benzyl bromide compounds in acetonitrile at room temperature afforded the 3-(2′-substituted benzyl)thiazolidin-2-cyanamide derivatives 1–13 in good yields. Compounds 1–13 were characterized by proton nuclear magnetic resonance (1H NMR) and infrared spectroscopies, of which the structures of the isomeric o-, m-, and p-fluoro derivatives 4–6 were established by single crystal X-ray crystallography. Compound 4 crystallizes in the monoclinic space group P21/n, with a = 9.177(19), b = 8.551(18), c = 14.090(3) A, β = 98.243(3)°, and Z = 4. The unit cell of 5 has a monoclinic P21/c symmetry with the cell parameters a = 9.289(2), b = 14.057(4), c = 8.574(2) A,  β = 100.350(3)°, and Z = 4. The unit cell of 6 also has a monoclinic P21/c symmetry with the cell parameters a  = 9.333(4), b = 14.034(5), c = 8.508(3) A, β = 99.15(5)°, and Z = 4. A series of 3-(2′-substituted benzyl)thiazolidin-2-cyanamide derivatives were efficiently synthesized via the reaction of benzyl bromide compounds with thiazolidin-2-cyanamide, of which the structures of the isomeric o-, m-, and p-fluoro derivatives were characterized by X-ray crystallography.