Sodium Hydroxide → 9-Bromo-3,4,7,8-tetrahydro-[1,4]diazepino[7,1-a]isoquinoline-2,5-dione

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Reaction Steps

2-(5-bromo-2-(2-((tert-butoxycarbonyl)amino)acetyl)-1,2,3,4-tetrahydroisoquinolin-1-yl)acetic acid. To a stirred solution of methyl 2-(5-bromo-2-(2-((tert-butoxycarbonyl)amino)acetyl)-1,2,3,4-tetrahydroisoquinolin-1-yl)acetate (113 g, 257 mmol) in EtOH (1000 mL), 4N aqueous NaOH (74.5 mL, 298 mmol) was added and the solution was stirred at RT for 2 h. The white precipitate was filtered off and the white solid was washed with a small amount of EtOH (1×) and diethyl ether (2×). The sodium salt was partitioned between 0.5N aqueous HCl and DCM, the organic layer was separated and washed with 0.5N aqueous HCl (1×) and brine (1×). The combined organic layers were dried with sodium sulfate, filtered and the solvent was removed under reduced pressure. The residue was dried under high vacuo overnight to yield the title compound as white foam (110 g). UPLC-MS: MS 427.2/429.2 (M+H+); UPLC rt 0.98 min.

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