1,3-Dibromo-5,5-dimethylhydantoin → HCID 22823421, compound

Participants

Reaction Steps

A solution of 1α,3β,24(R)-triethoxycarbonyloxycholest-5-ene (3.49 g, 5.5 m moles), dry hexane (58 ml) and 1,3-dibromo-5,5-dimethylhydantoin (998 mg, 3.3 m moles) was boiled under the irradiation of infrared rays for 15 minutes. The reaction mixture was cooled, and the resulting 5,5-dimethylhydantoin and the excessive 1,3-dibromo-5,5-dimethylhydantoin were removed by filtration. The filtrate was concentrated at reduced pressure to afford a residual product. Xylene was added to this substance to form a solution. The resulting solution was added dropwise to a solution held 170° C. of s-collidine (14.5 ml) in dry xylene (19 ml), and the reaction was carried out for additional 20 minutes. After the reaction, the hydrobromide of s-collidine was removed by filtration and the filtrate was concentrated under reduced pressure at 40° C. to give residual product. The residue was dissolved in ethylacetate (200 ml). The organic phase was washed with 1 N hydrochloric acid (3×10 ml), saturated sodium bicarbonate solution and water, and dried over anhydrous sodium sulfate. The drying agent was removed by filtration and the filtrate was concentrated under reduced pressure to give 3.68 g of residual product.

Provenance & Evidence