Hydrochloric Acid → HCID 54285910, compound

Participants

Reaction Conditions

Reaction Steps

A cooled solution of 12.08 g (0.036 mol) of cis-2-(2-chloroethyl)-2,3,5,8-tetrahydro-1,3-dioxo-8-phenyl-1H-1,2,4-triazolo[1,2-a]pyridazine-5-carboxylic acid in 180 ml of methanol was treated with a solution of 2.37 g (0.036 ml) of potassium hydroxide in 15 ml of methanol. The methanol was removed by evaporation and the residue was dissolved in 150 ml of dimethyl sulphoxide. The solution was treated with 4.90 g (0.043 mol) of potassium thioacetate and the mixture was stirred at 80° C. for 20 hours. The cooled mixture was diluted with 150 ml of water, acidified with 2-M hydrochloric acid and extracted with ether. The combined extracts were dried over magnesium sulphate and evaporated to give a yellow oil which was treated with diazomethane in the usual manner. The resulting yellow oil was chromatographed on silica gel using chloroform/ethyl acetate (4:1) for the elution to give 3.8 g (27%) of methyl trans-2-(2-acetylthioethyl)-2,3,5,8-tetrahydro-1,3-dioxo-8-phenyl-1H-1,2,4-triazolo[1,2-a]pyridazine-5-carboxylate of melting point 101°-102° C. (from ethyl acetate) and 0.1 g (1%) of methyl cis-2-(2-acetylthioethyl)-2,3,5,8-tetrahydro-1,3-dioxo-8-phenyl-1H-1,2,4-triazolo[1,2-a]pridazine-5-carboxylate in the form of a colourless oil.

Provenance & Evidence