Ammonia → 3-(diphenyl-phosphino)isoquinolin-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

At −78° C., 130 ml of ammonia were condensed in and 2.10 g of sodium (91.3 mmol) were dissolved therein within 5 min. The dark blue solution was admixed with 11.70 g of triphenylphosphine (44.6 mmol) in portions and stirred at −78° C. for 2 h. After 100 ml of dry tetrahydrofuran had been added, the cold bath was removed and the ammonia evaporated off within 2 h. After the orange-colored solution had been warmed to room temperature, it was admixed with 4.0 g (22.3 mmol) of 3-chloroisoquinolin-1(2H)-one from example 16.4 in portions and heated to 60° C. for 20 h. After the mixture had been cooled, it was admixed with 50 ml of dist. H2O, and the aqueous phase was extracted three times with 100 ml each time of dichloromethane, and the combined organic phases were dried over MgSO4 and concentrated under reduced pressure. The resulting solid was digested with dichloromethane, filtered off and dried. The filtrate was concentrated and the resulting solid again digested with dichloromethane, filtered off and dried. The solids were combined. 4.47 g (13.6 mmol, 60.9%) of 3-(diphenyl-phosphino)isoquinolin-1(2H)-one were obtained. The filtrate was concentrated under reduced pressure and the resulting solid purified by column chromatography (5:1 dichloromethane/ethyl acetate). A further 0.216 g (0.66 mmol, 2.9%) of 3-(diphenylphosphino)isoquinolin-1(2H)-one was obtained.

Provenance & Evidence