Phosgene → 3(R)-(2-Oxo-2,3-dihydro-benzoimidazol-1-yl)-piperidine-1-carboxylic Acid Tert-Butyl Ester

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Reaction Steps

To a solution of 3(R)-(2-Amino-phenylamino)-piperidine-1-carboxylic acid tert-butyl ester (52 mg, 0.18 mmol), Et3N (1.0 ml) in CH2Cl2 (1 ml) at 0° C. was added a solution of phosgene (20% in toluene, 0.1 ml). After stirring for 2 hr and evaporation of solvent, the residue was purified by chromatography (1%-2% MeOH in CH2Cl2) to give a colorless oil (34 mg, 60%). 1H-NMR (300 MHz, CDCl3) δ 7.80 (d, 1H), 4.20 (m, 3H), 3.50 (m, 1H), 2.75 (m, 1H), 2.65 (m, 1H), 2.10 (m, 1H), 1.90 (m, 1H), 1.70 (m, 1H), 1.50 (s, 9H) ppm; IR (film) 3067, 2975, 2935, 2858, 1745, 1692, 1612, 1487, 1423, 1383, 1347, 1266, 1246, 1158 cm−1; LRMS (calculated for C17H23N3O3-BOC)+ 217, found 217.

Provenance & Evidence