反应详情

(c) A solution of 1.27 g of tert.butyl hexahydro-1,3-dioxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxyate in 10 ml of dimethylformamide was added to a suspension of 0.4 g of sodium hydride in dimethyformamide. The mixture was stirred at room temperature until the evolution of gas had ceased. 1.86 g of S-bromoethyl thioacetate were added and the mixture was heated at 75° C. for 5 hours. Working-up in the same manner as described in paragraph (D) (a) earlier gave 0.15 g (7%) of tert.butyl 2,2- bis(acetylthiomethyl)-hexahydro-1,3-dioxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate in the form of a white solid having a melting point of 85°-86° C. (from diethyl ether/hexane).

1. temperaturethe mixture was heated at 75° C. for 5 hours