Dimethyl Sulfoxide → HCID 19016835, compound

Participants

Reaction Steps

To a solution of 14.8 g of 2-(4-methoxyphenyl)-4,4a,5,6-tetrahydrothieno[2',3':2,3]thiepino[4,5-c]-pyridazin-3(2H)-one in 100 ml of 30% hydrogen bromide-acetic acid is added 6.1 ml of dimethylsulfoxide with stirring at room temperature. The mixture is stirred for 4 hours at room temperature, poured into ice-cold water and extracted with chloroform. The extract is washed with water, dried and concentrated under reduced pressure. The resulting crystals are recrystallized from a mixed solvent of toluene and isopropyl ether to give 10 g of 2-(4-methoxyphenyl)-5,6-dihydrothieno[2',3':2,3]thiepino[4,5-c]pyridazin-3(2H)-one as white crystals, melting at 126°-128° C.

Provenance & Evidence