The title compound crystallizes in the triclinic space group p -1, with a = 8.474(5) Å, b = 9.402(5) Å, c = 11.239(5) Å, α = 98.133(5)° , β = 108.117(5)°, γ = 108.575(5)°, V=777.4(7) Å3 and the number of molecules in the unit cell Z=2. In the title compound, C15H18N2O4S, the dihydropyrimidine ring adopts a boat conformation. The dihedral angle between the benzene and tetrahydropyrimidine is 80.29(8)Ëš. In the crystal, molecules are linked via pairs of C—H…S hydrogen bonds, forming inversion dimmers with an R22(12) ring motif. The crystal structure is further stabilized by an intramolecular C—H…O hydrogen bonds forming a closed six membered ring