Hydrazine hydrate (1:1) → HCID 12687102, compound

Participants

Reaction Steps

5.0 g of 9-carboxy-4-fluoro-10,11-dihydrodibenzo[b,f]thiepin-11-one and 5.0 g of 100% hydrazine hydrate were dissolved in the mixed solvent of 50 ml of ethanol and 50 ml of dioxane. The resulting mixture was heated under reflux for 5 hours. The solvent was evaporated under reduced pressure to obtain the residue, which was washed with ethanol. To this was added 5.0 g of sodium hydroxide in 100 ml of diethylene glycol and the resulting mixture was heated with stirring at 180°-200° C. for 2 hours. After cooling, water was added to the mixture, which was extracted with benzene. The aqueous layer was acidified with hydrochloric acid and extracted with ethyl acetate. The extract was washed with water and dried over anhydrous sodium sulfate. The solvent was evaporated to obtain a glutinous residue which was chromatographed over silica gel, and eluted with benzene-ethyl acetate (1:1). Recrystallization of the thus obtained crude product from methanol-water afforded 600 mg of 9-carboxy-4-hydroxy-10,11-dihydrodibenzo[b,f] thiepin having a melting point of 171°-173° C.

Provenance & Evidence