Synthesis and X-ray structural studies of the dextro-rotatory enantiomer of methyl α-5(4,5,6,7-tetrahydro(3,2-c)thieno pyridyl) (2-chlorophenyl)-acetate isopropylsulfate

This study resolves conflicting data on a particular salt of the enantiomer of methyl α-5(4,5,6,7-tetrahydro(3,2-c)thieno pyridyl) (2-chlorophenyl)-acetate (S(+)clopidogrel). The title compound, (C16H17ClNO2S)+ (C3H7O4S)−, was obtained and successfully characterized by X-ray diffraction, NMR, TG/DSC/MS. This salt previously reported in the literature as a 2-propanol solvate of the hydrogensulfate salt appears to be actually an isopropylsulfate salt.