Sodium Hydroxide → 3-Benzyl-9-oxa-3,7-diazabicyclo[3.3.1]nonane

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Reaction Conditions

Reaction Steps

All volumes and equivalents are measured with respect to the amount of 3-benzyl-9-oxa-3,7-diazabicyclo[3.3.1]nonane dihydrochloride (see step (iv) above) used. Toluene (420 mL, 7 vols) and aqueous sodium hydroxide solution (2M, 420 mL, 7 vols, 4.0 eq) were added to 3-benzyl-9-oxa-3,7-diazabicyclo[3.3.1]nonane dihydrochloride (60.07 g, 206.03 mmole, 1.0 eq., see step (iv) above). The mixture was stirred under nitrogen, heated to 60° C. and held at this temperature for 30 minutes by which time two clear layers had formed. The lower, aqueous layer was removed, and the toluene solution of title compound (free base) was azeodried at atmospheric pressure (total volume of solvent removed=430 mL; total volume of toluene added=430 mL), then concentrated to a volume of 240 mL (4 vols). Karl Fischer analysis at this stage showed 0.06% water in the solution. The dried solution of title compound (theoretically 44.98 g, 206.03 mmole, 1:0 eq) was used as such in a subsequent step.

Provenance & Evidence