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

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Reaction Steps

9-bromo-1,3,4,7,8,12b-hexahydro-[1,4]diazepino[7,1-a]isoquinoline-2,5-dione. To a stirred solution of 2-(5-bromo-1-(carboxymethyl)-3,4-dihydroisoquinolin-2(1H)-yl)-2-oxoethanaminium chloride (88 g, 242 mmol) and triethylamine (169 mL, 1210 mmol) in DCM (960 mL), T3P (212 mL, 363 mmol, 50% m/m in AcOEt) was added slowly (exotherm) and the suspension was stirred at rt for 1 h. The solvent was reduced to a small amount under reduced pressure and the thick suspension was treated with 2N aqueous HCl (500 mL). The white suspension was stirred at RT for 15 min and the solid was filtered off. The solid was again treated with 2N aqueous HCl (300 mL), stirred for 10 min and filtered of. The slightly yellow solid was washed with water (1×) and with diethyl ether (2×). The resulting solid was dried at 50° C. under high vacuo overnight to yield the title compound as beige solid (71 g). UPLC-MS: MS 309.1/311.1 (M+H+); UPLC rt 0.72 min.

Provenance & Evidence