Nitromethane → 6-Nitromethyl-4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxylic acid ethyl ester

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Reaction Steps

4-Oxo-7,8-dihydro-4H-cyclohepta[b]pyrrole-1,3-dicarboxylic acid 1-tert-butyl ester 3-ethyl ester (6.81 g, 21.3 mmol) is dissolved in CH3NO2 (50 ml), Triton B (40% aqueous, 2.5 mL) is added quickly. The reaction mixture was kept at 80° C. for 8 h. The mixture is cooled and the solvent removed under reduced pressure. The residue is taken into 50 ml CH2Cl2 and 25 ml H2O. The aqueous phase is adjusted to slightly basic with 1N HCl and sat. NaHCO3, and extracted with CH2Cl2 (30 mL×4). Organic phases are combined, dried (Na2SO4), and evaporated. Flash chromatography (1:1 hexanes/EtOAc) provides the title compound (5.6 g, 93%) as white solid. 1H NMR (400 MHz, CD3OD) δ 7.21 (1H, s), 4.45 (2H, d), 4.20 (2H, q), 2.97-2.62 (5H, m), 2.04 (1H, m), 1.65 (1H, m), 1.27 (3H, t). MS (ES+) 281 (M+1) Step 2: Dimethylaminomethyl4-oxo-1,4,5,6,7,8-hexahydro-cyclohepta[b]pyrrole-3-carboxylic acid ethyl ester.

Provenance & Evidence