Sodium hydride → 6-(2,2-Dimethyl-3-sulfamoyl-1-propoxy)-7,8,9,10-tetrahydroimidazo[2,1-a]phthalazine

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Reaction Steps

0.59 g of 60% oily sodium hydride was suspended in 20 ml of dimethylformamide. To this suspension, 1.18 g of 3-hydroxy-2,2-dimethyl-1-propanesulfonamide was added, followed by stirring at room temperature (15° to 20° C.) under reduced pressure for 30 minutes. To this mixture was added 1.35 g of 6-chloro-7,8,9,10-tetrahydroimidazo[2,1-a]phthalazine, followed by stirring at 60° C. for 1.5 hours. After dimethylformamide was distilled off under reduced pressure, ice water was added to the residue, which was subsequently adjusted to pH 6 by the addition of 5 N hydrochloric acid and then extracted with ethyl acetate-tetrahydrofuran (2:1). The extract was washed with 20 ml of saturated saline and then dried over magnesium sulfate. After the solvent was distilled off under reduced pressure, the residue was subjected to silica gel column chromatography and eluted with dichloromethane-ethyl acetate-methanol (20:20:1). The fraction containing the desired product was concentrated, and ethyl ether was added to separate a crystal, which was collected by filtration, to yield 0.66 g of the title compound.

Provenance & Evidence