Hydrochloric Acid → 1,2,3,4-Tetrahydro-isoquinoline-1-carboxylic acid methyl ester hydrochloride

Participants

Reaction Steps

A solution of 2-(tert-butyoxycarbonyl)-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid (0.500 g, 1.80 mmol), potassium carbonate (0.324 g, 2.34 mmol), and iodomethane (0.384 g, 2.70 mmol) in 3 mL of DMF was stirred at rt for 3 hours. The mixture was diluted with ethyl acetate, washed with saturated aqueous sodium bicarbonate and brine, dried over sodium sulfate, filtered, and concentrated in vacuo. To a solution of the resultant residue (0.400 g, 1.37 mmol) was added 4 N HCl in dioxane (2.06 mL, 8.22 mmol). After 2 hours, the reaction was concentrated in vacuo to provide the title compound as a beige solid that gave a mass ion (ES+) of 192.2. This crude intermediate was used to prepare Example 12, by the procedure described for Example 1.

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