Potassium Carbonate → Tert-butyl 7-(3,3-dimethyl-2-oxobutyl)-9-oxa-3,7-diazabicyclo[3.3.1]nonane-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl 9-oxa-3,7-diazabicyclo[3.3.1]nonane-3-carboxylate hydrochloride (Preparation A; 0.26 g, 1.0 mmol) and K2CO3 (1.45 g, 10.5 mmol) in MeCN (8 mL) was treated with 1-chloropinacolone (0.216 g, 1.6 mmol), and the mixture stirred at 40° C. overnight. The following morning, the temperature was raised to 50° C. for 4 h before the solids were filtered off from the mixture and the filtrate concentrated in vacuo. The crude product was dissolved in DCM and the solution was added to an ion-exchange solid phase extraction plug (10 g CBA (carboxylic acid on silica support)). After 1 h, the plug was washed with DCM (15 mL), after which the product was finally eluted with dichloromethane:MeOH:TEA (90:5:5). The solvents were evaporated to give 0.276 g (85.5%) of the sub-title compound.

Provenance & Evidence