Dimethylformamide → 3-tert-butoxycarbonyl-7-chloro-6-(3-methoxycarbonyl-propyloxy)-2,3,4,5-tetrahydro-1H-benzo[d]azepine

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Reaction Steps

Add methyl 4-bromobutyrate (1.9 mL, 10.4 mmol) to a mixture of 3-tert-butoxycarbonyl-7-chloro-6-hydroxy-2,3,4,5-tetrahydro-benzo[d]azepine (310 mg, 1.0 mmol), DBU (0.23 mL, 1.6 mmol) and DMF (10 mL) at ambient temperature under nitrogen. Stir the reaction mixture for 16 h. Dilute with hexane/EtOAc (1:1, 60 mL), wash the mixture with 10% aqueous NaCl (4×25 mL), dry the organic layer over Na2SO4 and concentrate in vacuo. Purify by chromatography on silica gel eluting with hexane/EtOAc (19:1 to 2:3) to obtain 3-tert-butoxycarbonyl-7-chloro-6-(3-methoxycarbonyl-propyloxy)-2,3,4,5-tetrahydro-1H-benzo[d]azepine (303 mg, 73%). MS (ES+) m/z: 398 (M+H)+.

Provenance & Evidence