Trichloroacetic Acid → 8-Methoxy-2,3,4,5-tetrahydro-benzo[c]azepin-1-one

Participants

Reaction Steps

Following a procedure of Tomita, et. al., J. Chem. Soc. C 1969, 183, 7-methoxytetralone oxime (45.0 g, 0.235 mol) was mixed with solid trichloroacetic acid (150 g), and the resulting suspension heated to ca. 80 C., at which time a violent exotherm ensued, yielding a black solid mixture. The residue was cooled, partitioned between ethyl acetate and saturated aqueous sodium bicarbonate solution, and the combined organic layers were concentrated in vacuo. The residue was purified by chromatography over silica gel to yield 10.0 g (22%) of 8-methoxy-2,3,4,5-tetrahydro-1H-2-benzazepin-1-one. An analytical sample was obtained by recrystallization from CH2Cl2 /hexanes to yield colorless crystals: mp. 99°-101° C. (lit. (see above) 100°-101° C.); 1H NMR(CDCl3) d7.35(brs, 1H), 7.30(d, J=3 Hz, 1H), 7.10(d, J=9 Hz, 1H), 6.95(dd, J=3, 9 Hz, 1H), 3.82(s, 3H), 3.10(q, J=6 Hz, 2H), 2.80(t, J=6 Hz, 2H), 1.98(m, 2H).

Provenance & Evidence