Phosphorus oxychloride → (S)-2-(5-tert-Butyl-isoxazol-3-ylcarbamoyl)-perhydro-azepine-1-carboxylic acid tert-butyl ester

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Reaction Steps

Phosphorus oxychloride (0.88 g, 5.73 mmol) is added drop wise at 0° C. to a solution of perhydro-azepine-1,2-dicarboxylic acid 1-tert-butyl ester (0.93 g, 3.82 mmol) and 5-tert-butyl-isoxazol-3-ylamine (0.54 g, 3.82 mol) in pyridine (10.0 mL). The reaction mixture is slowly warmed up to room temperature and stirred for three hours. The mixture is diluted with EtOAc and washed twice with saturated NH4Cl solution. The organic phase is washed with 1N HCl, and after drying over anhydrous Na2SO4 the solvent is removed under reduced pressure to afford the crude product that is used in the next step without further purification; m/z 366 [M+H+].

Provenance & Evidence