Synthesis and Crystal Structure of Ethyl 2-Methylthio-7-phenylpyrazolo[1,5-a]pyrimidine-3-carboxylate

The crystal structure of ethyl 2-methylthio-7-phenylpyrazolol,5-a]pyrimidine-3- carboxylate (C16H15N3O2S, Mr = 313.37) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/n with a = 19.361(7), b = 7.595(3), c = 20.910(8) (A), β = 94.925(6)°, V= 3064(2) (A)3, Z = 8, Dc= 1.359 g/cm3,μ = 0.222 mm-1, F(000) = 1312, R = 0.0546 and wR = 0.1082 for 5374 unique reflections with 3419 observed ones (I ＞ 2σ(I)). The results show that all ring atoms in the pyrazolopyrimidine moiety are coplanar with strong tensile force. The structure analysis indicates that the single crystal contains strong nonclassical hydrogen bonds.