Hydrochloric Acid → 2-(Tert-butoxycarbonyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid

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Reaction Steps

2N Aqueous lithium hydroxide solution (73.6 mL, 147.23 mmol) was added to a solution of 1-ethyl 2-tert-butyl 6-methoxy-3,4-dihydroisoquinoline-1,2(1H)-dicarboxylate (8.23 g, 24.54 mmol) in a mixed solvent of EtOH (35 mL) and THF (35 mL) at room temperature, and the mixture was stirred for 2 hr. To the reaction mixture was added water, the pH of the mixture was adjusted to 3 with 2N hydrochloric acid, and the mixture was extracted with ethyl acetate (×3). The organic layer was washed with brine, and dried over magnesium sulfate, and the solvent was evaporated under reduced pressure to give 2-(tert-butoxycarbonyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (7.59 g, 24.70 mmol, quant.) as a colorless oil.

Provenance & Evidence