Potassium Carbonate → Tert-butyl 3-(4-nitrophenyl)-8-azabicyclo[3.2.1]oct-2-ene-8-carboxylate

Participants

Reaction Steps

A mixture of 1-bromo-4-nitrobenzene (2.0 g; 9.9 mmol; 1.0 eq.), tert-butyl 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-8-azabicyclo[3.2.1]oct-2-ene-8-carboxylate (4.3 g; 12.9 mmol; 1.30 eq.), PdCl2(dppf) (724 mg; 0.99 mmol; 0.1 eq.) and potassium carbonate (4.1 g; 29.7 mmol; 3.0 eq.) in Dioxane-1,4 (20 mL) and water (10 mL) was heated at 900 under nitrogen atmosphere O/N. The reaction mixture was filtered through a celite pad. The cake was rinsed with dichloromethane, phases were separated and organic phase was washed with water and brine. Organic phase was then dried over magnesium sulfate, filtered and concentrated. The crude was purified by flash chromatography on silica (heptane/EtOAc, gradient from 90:10 to 80:20) to give the title compound as a yellow solid (1.97 g; 60%). 1H NMR (300 MHz, DMSO-d6-d6) δ: 8.17 (d, J=9.0 Hz, 2H), 7.69 (d, J=9.0 Hz, 2H), 6.84 (d, J=5.3 Hz, 1H), 4.43 (t, J=5.3 Hz, 1H), 4.35 (m, 1H), 2.97 (d, J=17.5 Hz, 1H), 2.32 (d, J=17.5 Hz, 1H), 2.15 (m, 1H), 1.95-1.88 (m, 2H), 1.71-1.58 (m, 1H), 1.37 (s, 9H). HPLC (max plot) 89.0%; Rt %4.66 min. UPLC/MS: (MS+) 331.3.

Provenance & Evidence