Sulfuric Acid → HCID 46836962, compound

Participants

Reaction Steps

9-Benzyl-3-oxa-9-azabicyclo-(3.3.1)nonane (3.0 g, 13.8 mmol, see: WO 03004503) was dissolved in ethanol (100 ml), and 10% Pd/C (0.56 g) was added. The mixture was hydrogenated at 100 psi over night. The solids were filtered off, a solution of HCl in dioxane (4 ml, 4N) was added and the solvent evaporated. The residue was dissolved in dichloromethane (100 ml) and triethylamine (8 ml) and a solution of [2,1,3]-benzoxadiazole-5-carbonylchloride (3.5 g, 19.2 mmol) in dichloromethane (10 ml) was added. After stirring the mixture for 20 minutes, water (100 ml) and H2SO4 (→pH2) were added and the organic phase washed with sodium bicarbonate solution (100 ml), the aqueous was re-extracted with dichloromethane (100 ml) and the combined organic phase was dried over magnesium sulfate, and concentrated under vacuum. The crude material was purified by silica gel chromatography eluting with hexane/THF (70/30). The product crystallized, when the solvent was evaporated slowly, which yielded the title compound as a white solid (3.13 g): mp=128-130° C., LC-MS, MH+=274.2; 1H NMR (300 MHz, CDCl3) δ 7.94 (dd, 2H, J=9.0 and 1.2 Hz); 7.89 (t, 1H, J=1.2 Hz); 7.47 (dd, 1H, J=9.0 and 1.2 Hz); 4.62 (s, 1H); 4.05 (d, 1H, J=11.7 Hz); 3.95-3.89 (m, 2H); 3.79 (d, 1H, J=11.7 Hz); 3.66 (s, 1H); 2.71-2.54 (m, 1H); 2.14-1.69 ppm (m, 5H).

Provenance & Evidence