Proton sponge → HCID 69927702, compound

Participants

Reaction Conditions

Reaction Steps

500 mg (1.51 mmol) of tert-butyl 1-((tert-butyldimethylsilyloxy)methyl)-3-hydroxycyclobutylcarbamate (prepared by reduction of ethyl-1[[tert-butyloxy)carbonyl]amino]-3-hydroxycyclobutane-1-carboxylate as described in J. Med. Chem., 1990 33(10) 2905-2915) and proton sponge (N,N,N′,N′ tetramethylnapthalene-1,8 diamine) (1.63 g, 6.04 mmol) were dissolved in DCM (18 mL), cooled down to 0° C., and 447 mg (3.02 mmol) of trimethyloxonium borontetrafluoride was added in one portion as a solid under vigorous stifling. The reaction mixture was stirred for 3 h and diluted with DCM (50 mL) and brine (20 mL), added under vigorous stifling. The organic phase was washed with sodium bicarbonate, brine, dried over sodium sulphate, evaporated and purified on short silica column (DCM as an eluent). The resulting product was dissolved in THF (5 mL), and a solution of tetrabutylammonium fluoride in THF (1M, 4.5 mL) was added, and the reaction was stirred at room temperature for 4.5 h. The reaction was monitored by TLC and once deemed to have reached completion, it was absorbed onto silica and purified on silica (EtOAc-hexane 1:1 to neat EtOAc) to give the title compound (251 mg, 72%). LC/MS 232 (M+1).

Provenance & Evidence