Boron tribromide → HCID 178474486, compound

Participants

Reaction Conditions

Reaction Steps

Methylene chloride, 125 ml was stirred and cooled to -78° C. in an acetone-dry ice bath. Boron tribromide (7.5 ml, 0.079 mole) was added, followed by 42 (6.15 g, 0.025 mole). After a 10 minutes period at -78° C., the bath was removed and the mixture was stirred at ambient temperature under a CaCl2 drying tube for 18 hours. The mixture was quenched in ice and water (500 ml) and the resulting mixture was neutralized with saturated NaHCO3 solution to pH 7. The aqueous layer was separated and evaporated to dryness in vacuo. The residue was triturated with boiling IPA and filtered hot. Evaporation of the filtrate to dryness under reduced pressure left an oil that was chromatographed on silica gel. The product was eluted with 80CHCl3 --20CH3OH saturated with concentrated NH4OH and then triturated with CH3CN to yield 2.4 g (41%) of 43; m.p. 277°-279° C.

Provenance & Evidence