Water → 5-Bromo-1,2,3,4-tetrahydroisoquinolin-1-one

Reaction equation

C[O:2][C:3](=O)[NH:4][CH2:5][CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[Br:13].P(=O)(O)(O)O.O>C(OCC)(=O)C>[Br:13][C:8]1[CH:9]=[CH:10][CH:11]=[C:12]2[C:7]=1[CH2:6][CH2:5][NH:4][C:3]2=[O:2]

Participants

Procedure

1.36 g of methyl[2-(2-bromophenyl)ethyl]carbamate and 5.2 g of phosphoric acid are stirred under an inert atmosphere at a temperature close to 150° C. The reaction mixture is cooled to a temperature close to 20° C., then it is hydrolysed with a mixture of water and ethyl acetate using ultrasound treatment. After decanting, the organic phase is washed with a saturated aqueous solution of sodium hydrogen carbonate, water, a saturated aqueous solution of sodium chloride, then concentrated using a rotary evaporator under reduced pressure (5 kPa). 0.105 g of 5-bromo-3,4-dihydroisoquinolin-1(2H)-one is obtained in the form of an amorphous beige solid.