Cesium carbonate → 2-(2,2-Dimethyl-2,3-dihydrobenzofuran-7-yloxy)-3-nitropyridine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 2-chloro-3-nitropyridine (4.9 g, 30.9 mmol) in DMF (50 mL) was treated with 2,2-dimethyl-2,3-dihydrobenzofuran-7-ol (5.3 mL, 46.4 mmol) and cesium carbonate (30.2 g, 92.7 mmol). The mixture was heated at 80° C. for 10 h. The reaction was cooled to rt, and the mixture was poured in water (200 mL) with stirring. The yellow precipitate formed was filtered and washed with water, and recrystallized from ethanol (50 mL) to afford 134a as brown crystals (6.5 g, 73% yield). [M+H]+=287.16. 1H NMR (500 MHz, deuterochloroform) δ ppm 8.38 (dd, 1H, J=1.7 Hz, J=5.0 Hz), 8.31 (dd, 1H, J=5.0 Hz, J=1.7 Hz), 7.12 (dd, 1H, J=10.0 Hz, J=5.0 Hz), 7.05 (d, 1H, J=5.0 Hz), 7.00 (d, 1H, J=10.0 Hz), 6.86 (t, 1H, J=10.0 Hz), 3.05 (s, 2H), 1.39 (s, 6H); 13C (125 MHz, deuterochloroform) δ (ppm), 155.42, 151.76, 150.16, 136.03, 135.40, 134.04, 129.76, 122.60, 121.06, 120.37, 118.07, 88.40, 43.07, 27.98.

Herkunft & Nachweise