Borane → Benzyl 4-amino-3,3-dimethylpyrrolidine-1-carboxylate

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Reaction Steps

To a solution of (Z)-benzyl 4-(methoxyimino)-3,3-dimethylpyrrolidine-1-carboxylate (3.17 g, 11.5 mmol) in tetrahydrofuran (10 mL), was added borane in THF (24.1 mL, 24.1 mmol) at rt. The reaction was heated at reflux overnight. The reaction was cooled, quenched with 6N aq. sodium hydroxide, then diluted by water, and extracted with ether. The organic layer was dried over MgSO4, concentrated, and purified by silica gel chromatography, eluting with 0-20% methanol in dichloromethane to give benzyl 4-amino-3,3-dimethylpyrrolidine-1-carboxylate (1.92 g, 67.4 yield). 1H NMR (400 MHz, CHLOROFORM-d) δ 7.45-7.31 (m, 5H), 5.32 (s, 2H), 5.15 (s, 2H), 4.07-3.91 (m, 1H), 3.56 (dd, J=12.1, 6.4 Hz, 1H), 3.51-3.32 (m, 1H), 3.22-3.06 (m, 1H), 2.83-2.75 (m, 1H), 1.17 (s, 3H), 1.10 (s, 3H). MS (ES+) m/z: 248.2, 249.1 (M+H); LC retention time: 2.24 min (analytical HPLC Method I).

Provenance & Evidence