Trifluoromethanesulfonic anhydride → 5-bromo-2-(2-hydroxyethyl)-3,4-dihydroisoquinolin-1(2H)-one

Participants

Reaction Conditions

Reaction Steps

1.5 g of methyl[2-(2-bromophenyl)ethyl](2-ethoxyethyl)carbamate are dissolved under an inert atmosphere in 140 cm3 of dichloromethane at a temperature close to 20° C. 1.6 g of 4-dimethylaminopyridine are added to the reaction mixture, which is cooled to a temperature in the vicinity of 0° C. 3.7 cm3 of trifluoromethanesulfonic anhydride in solution in 15 cm3 of dichloromethane are poured in to the reaction mixture over 30 min. The suspension is kept stirring for 1 h at 0° C., then for 48 h at a temperature close to 20° C. 100 cm3 of a saturated aqueous solution of sodium hydrogen carbonate are added to the reaction medium. Stirring is continued for 1 h at a temperature close to 20° C. After decanting, the organic phase is washed with 100 cm3 of a 20% aqueous solution of acetic acid then with 150 cm3 of a saturated aqueous solution of sodium hydrogen carbonate, dried over magnesium sulfate, filtered and concentrated using a rotary evaporator under reduced pressure (5 kPa). The crude product obtained is purified by filtration through a bed of silica of 20 g. The latter is washed with 100 cm3 of ethyl acetate. The filtrate is concentrated using a rotary evaporator under reduced pressure (5 kPa). 0.8 g of 5-bromo-2-(2-hydroxyethyl)-3,4-dihydroisoquinolin-1(2H)-one is obtained in the form of a beige oil.

Provenance & Evidence