Boron tribromide → HCID 57039022, compound

Participants

Reaction Steps

(3S,4R)-4-(2-Chloropyrimidin-4-yl)amino-3,4-dihydro-3-hydroxy-6-(3-methoxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (0.23 g) (see Preparation 19) was dissolved in dichloromethane (25 ml) (the flask was fitted with a calcium chloride drying tube) and boron tribromide (1 ml) was added. The mixture was stirred at room temperature for 24 hours and a precipitate was formed. The dichloromethane was decanted off, the solid taken up in 1N aqueous sodium hydroxide and washed with ethyl acetate. The aqueous phase was acidified to give a gum which was collected and dried under reduced pressure at 70° C. to yield (3S,4R)-4-(2-chloropyrimidin-4-yl)amino-3,4-dihydro-3-hydroxy-6-(3-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (0.123 g) as a white solid, m.p.>280° C. LRMS m/z=475 (m)+.

Provenance & Evidence