Hydrochloric Acid → 4-Bromo-6,7-dihydro-8(5H)-isoquinolinone

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Reaction Steps

The crude methyl 4-bromo-8-oxo-5,6,7,8-tetrahydroisoquinoline-7-carboxylate (7.79 g, 27.4 mmol) was dissolved (small amount of not dissolved material) in aq. 6M HCl (84.1 ml, 505 mmol) and heated at reflux for 2.5 h. The acidic solution was concentrated in vacuo, suspended in water (ca. 25 mL), cooled in ice and basified with 6.0 M KOH. The aqueous solution was extracted with ether (2×) and CH2Cl2 (3×), the combined organic layers were dried over Na2SO4, filtered and concentrated to afford the title compound (4.30 g, 69%) as a brown solid. MS: 226.0 (M+H+, 1Br).

Provenance & Evidence