Methyl chloroformate → HCID 58147176, compound

Participants

Reaction Conditions

Reaction Steps

To a 50-mL round-bottom flask charged with THF (15 mL) cooled to −78° C. under an N2 atmosphere was slowly added tert-butyllithium (0.922 mL, 1.474 mmol, 1.6 M in pentane). At this temperature, tert-butyl 7-bromo-1,3,4,5-tetrahydro-2H-2-benzazepine-2-carboxylate (0.37 g, 1.134 mmol) in THF (4 mL) was added. The resulting solution was stirred at −78° C. for 10 min. To the reaction flask was quickly added methyl chloroformate (1.75 mL, 22.68 mmol), and the resulting mixture was stirred at −78° C. for 30 min then warmed to room temperature for 10 min. The solvent was evaporated under reduced pressure and the residue was partitioned between water (10 mL) and EtOAc (50 mL). After separation, the aqueous phase was extracted with EtOAc (2×15 mL), the combined organic phases were washed with brine (10 mL), dried over anhydrous MgSO4, and concentrated. Flash column chromatography (EtOAc:hexanes, 0-10%) provided 2-tert-butyl 7-methyl 1,3,4,5-tetrahydro-2H-2-benzazepine-2,7-dicarboxylate (0.142 g, 41%) as a slightly yellow solid. 1H NMR (CDCl3, 400 MHz) δ 7.83-7.80 (m, 2H), 7.24 (d, J=7.6 Hz, 1H), 4.45 (br, 0.7H), 4.40 (br, 1.3H), 3.90 (s, 3H), 3.68 (br, 2H), 3.00 (br, 2H), 1.78 (m, 2H), 1.37 (s, 9H).

Provenance & Evidence