3-oxa-9-azabicyclo[3.3.1]nonan-7-one;hydrochloride

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 3-oxa-9-azabicyclo[3.3.1]nonan-7-one hydrochloride (CAS 1126795-00-3, 2.82 g), TEA (6.12 g, 60 mmol, 3.0 eq) and 2-Nitro-benzenesulfonyl chloride (8.84 g, 40 mmol, 2.0 eq) in DCM (100 mL) was stirred at room temperature for 10 h. Then the solvent was removed in vacuo, the residue was purified by silica gel (EA/PE=1:3) to give 9-(2-nitrophenyl)sulfonyl-3-oxa-9-azabicyclo[3.3.1]nonan-7-one 107b as a white solid, 4.90 g, yield: 75%. MS: calc'd (MH+) 327, measured (MH+) 327. Then the solvent was removed in vacuo the residue was purified by silica gel (EA/PE=1:3)

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 3-oxa-9-azabicyclo[3.3.1]nonan-7-one hydrochloride (CAS 1126795-00-3) (10 g) was dissolved in 200 ml of dichloromethane which was cooled to 0° C. Then, CbzCl (14.3 g, 84.7 mmol) was added to the mixture followed by the dropwise addition of a solution of TEA (14.6 ml, 112.8 mmol) in 20 ml of dichloromethane. The mixture was allowed to warm up to room temperature. After stirring 2 h, it was quenched with 20 ml of a saturated aqueous solution of NaHCO3. The two layers were separated and the aqueous layer was extracted with dichloromethane (3×150 ml). The combined organic layers were washed with water, dried over Na2SO4 and the solvent was evaporated under reduced pressure. The crude product was purified by chromatography on silica gel, yielding 10.1 g of benzyl 7-oxo-3-oxa-9-azabicyclo[3.3.1]nonane-9-carboxylate 100b (64%). to warm up to room temperature it was quenched with 20 ml of a saturated aqueous solution of NaHCO3 The two layers were separated the aqueous layer was extracted with dichloromethane (3×150 ml) The combined organic layers were washed with water dried over Na2SO4 the solvent was evaporated under reduced pressure The crude product was purified by chromatography on silica gel