Sodium bis(trimethylsilyl)amide → N-tert-Butyl-2-(2,4-dioxo-5-phenyl-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl)-N-phenyl-acetamide

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Reaction Steps

To a stirred solution of 600 mg (2.38 mmol) 1-Phenyl-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-2,4-dione in 16 mL DMF is added 2.62 mL (2.62 mmol, 1.1 equiv) of 1M Sodium bis(trimethylsilyl)amide in THF at ambient temperature and stirred 0.5 h. To this solution is added 707 mg (2.62 mmol, 1.1 equiv) 2-Bromo-N-tert-butyl-N-phenyl-acetamide, prepared as in Part A, in 4 mL DMF and stirred 18 h at ambient temperature. The solvent is removed in vacuo and the residue taken into 50 mL EtOAc, washed successively with H2O (30 mL), 1N HCl (30 mL), satd. NaHCO3 (30 mL), and brine (30 mL), dried (MgSO4), filtered and concentrated in vacuo to a brown oil. The crude product is purified by flash chromatography on 40 g silica gel eluted successively with EtOAc/Hexanes (2:3, 500 mL), (1:1, 750 mL). Appropriate fractions were combined and concentrated in vacuo to give 748 mg (1.69 mmol) of N-tert-Butyl-2-(2,4-dioxo-5-phenyl-2,3,4,5,-tetrahydro-benzo[b][1,4]diazepin-1-yl)-N-phenyl-acetamide as a white foam: 1H NMR (CDCl3, 300 MHz) δ7.45-7.21 (m, 12H), 7.08 (t, 1H), 6.90 (m, 1H), 4.30 (d, 1H, J=16.4), 3.85 (d, 1H, J=16.6), 3.59 (d, 1H, J=12.0), 3.49 (d, 1H, J=11.9), 1.43 (s, 9H); TLC Rf =0.24 (EtOAc/Hexanes, 1:1).

Provenance & Evidence