Hydrochloric Acid → HCID 20435967, compound

Participants

Reaction Steps

3.45 g (30 mmol) of methanesulfonyl chloride were added dropwise to a stirred solution, cooled at 0° C., of 6.7 g (25 mmol) of methyl 2,3,5,8-tetrahydro-2-(2-hydroxyethyl)-2-methyl-1,3-dioxo-1H-pyrazolo[1,2-a]-pyridazine-5-carboxylate in 20 ml of dry pyridine. After 2 hours, the resulting suspension was poured on to ice/water and acidified with 2M hydrochloric acid. Extraction with dichloromethane then yielded 7.84 g (75%) of methyl 2,3,5,8-tetrahydro-2-(2-methanesulfonyloxyethyl)-2-methyl-1,3-dioxo-1H-pyrazolo[1,2-a]pyridazine-5-carboxylate having a melting point of 104°-105° C. (from diethyl ether).

Provenance & Evidence