Triethylamine → (5,7-Dibromo-adamantan-2-yl)-carbamic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A suspension of the acid 24 (2.00 g, 5.92 mmol) in dry toluene (30 mL) was treated successively with Et3N (1.0 mL, 7.10 mmol) and diphenylphosphoryl azide (DPPA, 1.6 mL, 7.10 mmol). The resulting mixture was stirred at 85° C. for 15 h. To a separated flask containing a solution of t-BuOK (1.35 g, 11.8 mmol) in dry THF (80 mL) at 0° C. was added the isocyanate solution dropwise via a dropping funnel. The resulting reaction mixture was allowed to warm to rt over 30 min, and then it was quenched with water. The THF was removed in vacuo, and the resulting material was diluted with EtOAc. The organic layer was washed with 1N HCl, sat. NaHCO3 and brine, dried (Na2SO4), filtered and concentrated in vacuo. Flash chromatography (SiO2, 95:5 to 8:2, hexanes/EtOAc) afforded 1.20 g (50%, 2 steps) of the title compound as a white powder. 1H NMR (300 MHz, CDCl3) δ4.68 (bs, 1 H), 3.76 (bs, 1 H), 2.87 (s, 2 H), 2.47-2.13 (m, 10 H), 1.46 (s, 9 H).

Provenance & Evidence