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

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Reaction Steps

(rac)-4-Bromo-7-methyl-8-oxo-5,6,7,8-tetrahydro-isoquinoline-7-carboxylic acid methyl ester (3.3 g, 11.0 mmol) was dissolved in aq. 6 N HCl (28.0 mL, 168 mmol) and heated at reflux for 2.5 h. The acidic solution was concentrated in vacuo, re-suspended in water (ca. 25 mL), cooled in an ice-water bath, and basified with 6 N aq. KOH solution. The aqueous solution was then washed with Et2O (2×) and CH2Cl2 (3×). The combined organic layers were dried over Na2SO4, filtered and concentrated in vacuo to afford the title compound (2.38 g, 90% yield) as a brown solid. MS: 240.1 & 242.1 (M+H)+.

Provenance & Evidence