Hydrochloric Acid → tert-Butyl 2-oxo-7-azabicyclo(2.2.1)heptane-7-carboxylate

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Reaction Conditions

Reaction Steps

To 180 mg (0.970 mmol) of the diastereomer mixture obtained in Example 10, 7-(t-butoxycarbonyl)-3-methoxycarbonyl-7-azabicyclo[2.2.1]heptan-2-one, was added 3 ml of 10% HCl and the resulting mixture was heated under reflux at 100° C. for 3.5 hours. After completion of the reaction the solvent was evaporated in vacuo and the remaining water was removed by azeotropic distillation with ethanol. The crude product obtained was dissolved with 10 ml of dry methylene chloride, 169 ml (1.68 mmol) of Et3N and 292 mg (1.34 mmol) of (Boc)2O were added to the solution and the resulting mixture was stirred at room temperature for 12 hours. After completion of the reaction, the reaction mixture was poured into a saturated aqueous sodium chloride solution, then extracted with chloroform, the extract was dried with Na2SO4, then filtrated and the solvent was evaporated in vacuo. The crude product thus obtained was purified by silica gel chromatography (AcOEt:hexane=1:3) to obtain 91.0 mg of 7-(t-butoxycarbonyl)-7-azabicyclo[2.2.1]heptan-2-one. Yield 64%.

Provenance & Evidence