反应详情

A mixture of 7-Bromo-2,3-dihydro-benzo[1,4]dioxin-6-ylamine (14.8 g, 64.3 mmol, 1 eq), triethyl orthoformate (12.7 cm3, 77.2 mmol, 1.2 eq) and 2,2-dimethyl-[1,3]dioxane-4,6-dione (Meldrum's acid) (11.1 g, 77.2 mmol, 1.2 eq) in ethanol (70 mL) was heated to reflux. After 1 hour the mixture was allowed to cool to room temperature then filtered, washing with ethanol then ether, to afford a white solid (22.9 g, 93%). LC/MS (ES) m/z 384 (MH+ 100%); 1H-NMR (400 MHz, d4-DMSO), 11.43 (1H, br d, J=20, NH), 8.6 (1H, d, J=12, NCH═C), 7.49 (1H, s, CHCBr), 7.28 (1H, s, CHCN), 4.30-4.27 (4H, m, 2×(CH2O)), 1.68 (6H, s, (CH3)2C)

1. temperaturewas heated to reflux
2. filtrationthen filtered
3. washwashing with ethanol