Phosphorus tribromide → 8-(1-bromoethyl)-2-morpholino-6-(pyrrolidine-1-carbonyl)-4H-chromen-4-one

Participants

Reaction Conditions

Reaction Steps

A solution of tribromophosphine (0.491 mL, 5.22 mmol) in 1,2-dichloroethane (4 mL) at 10° C., was added dropwise to 8-(1-hydroxyethyl)-2-morpholino-6-(pyrrolidine-1-carbonyl)-4H-chromen-4-one (1.62 g, 4.35 mmol) suspended in 1,2-dichloroethane (18 mL) under nitrogen. The resulting suspension was stirred at 50° C. for 1 hour. The reaction mixture was allowed to cool to RT under stirring and diluted with diethyl ether (18 mL). The precipitate was collected by filtration, washed with diethyl ether and dried to a constant weight to afford 8-(1-bromoethyl)-2-morpholino-6-(pyrrolidine-1-carbonyl)-4H-chromen-4-one (2.45 g, 100%) hydrobromide as a white solid, which was used without further purification. NMR Spectrum (DMSOd6): 1.79-1.93 (m, 4H), 2.11 (d, 3H), 3.37-3.44 (m, 2H), 3.46-3.53 (m, 2H), 3.57-3.70 (m, 4H), 3.73-3.80 (m, 4H), 5.66 (s, 1H), 5.92 (q, 1H), 7.99-8.03 (m, 2H).

Provenance & Evidence