Analytical studies on the hydrolysis of Chinoin-102 and Chinoin-127, candidate compounds for stability studies

The isolation and structural elucidation of some products of hydrolytic studies with two drugs, Chinoin-102 and Chinoin-127, are described. CH-127 is 1,6(ax)-dimethyl-4-oxo-1,6,7,8,9,9a-hexahydro-4H-pyrido-[1,2-a]-pyrimidine-3-carboxamide. CH-102 is 8,9-dimethoxy-3-imino-5,6-dihydro-3H-thiazolo-[4,3-a]-isoquinoline-1-carbonitrile. Degradation of the active compounds was studied by hydrolysing them in acidic, neutral and alkaline media. The isolated degradation products were identified by MS and IR techniques. The products identified were: for CH-127, 1,6-dimethyl-4-oxo-1,6,7,8-tetrahydro-4H-pyrido-[1,2-a]-pyrimidin-3-carboxamide; for CH-102, acid amide and acid derivatives. For the selective determination of the drugs and their degradation products, UV spectrophotometric and densitometric methods were applied.