Carbamic acid, N-[2-(3-methoxyphenyl)ethyl]-, ethyl ester → 6-methoxy-3,4-dihydroisoquinolin-1(2H)-one

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Reaction Steps

A mixture of ethyl 3-methoxyphenethylcarbamate (7.32 g, 32.8 mmol) and polyphosphoric acid (30 g) was heated at 120° C. for 2 h after which H2O (100 mL) was added and the mixture was cooled to RT. The mixture was extracted with EtOAc (6×100 mL), dried (MgSO4) and concentrated to yield crude 6-methoxy-3,4-dihydroisoquinolin-1(2H)-one (8.0 g, 138%) as a sticky gum. 1H NMR (400 MHz, acetone-d6): δ 7.88 (d, J=8.4 Hz. 1H), 7.04 (brS, 1H), 6.87 (dd, J=8.4, and 2.4 Hz, 1H), 6.82 (d, J=2.4 Hz, 1H), 3.84 (s, 3H), 3.49 (t, J=6.4 Hz, 2H), 2.94 (t, J=6.2 Hz, 2H); MS (ESI) m/z: 178.0 (M+H+).

Provenance & Evidence