Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → 2-Oxo-3-phenethyl-3,10-diaza-bicyclo[4.3.1]decane-10-carboxylic Acid tert-Butyl Ester

Participants

Reaction Conditions

Reaction Steps

2-(2,2-Dimethoxy-ethyl)-6-phenethylcarbamoyl-piperidine-1-carboxylic acid benzyl ester (Compound 239, 0.297g, 0.65mmol) was dissolved in toluene (15 ml), and the flask was immersed in a 80° C. oil bath. Pyridinium p-toluene sulfonate (0.0120 g, 0.05 mmol) was added and the reaction was stirred at 80° C. for 2 hours. After this time, the reaction was cooled down and the precipitate formed was removed by filtration. The toluene was evaporated and the residue was dissolved in dioxane (10 mL). N-(tert-Butoxycarbonyl anhydride (0.285 g, 1.31 mmol) and palladium 10% on activated carbon (0.1 g) were added. Hydrogen was applied via Parr apparatus and reaction was shaken at 50 psi for 12 hours. The black suspension was then filtered through compacted Celite, and dioxane was removed. Flash chromatographic purification of the residue (1:2 EtOAc/hexanes) gave Compound 240 (0.211 g, 90%). Rf=0.31 (1:2 EtOAc/hexanes).

Provenance & Evidence