反应详情

温度

180 °C

A mixture of 2,3-diaminotoluene (2.44 g, 20 mmol), (E)-cinnamic acid (2.96 g, 20 mmol) and polyphosphoric acid (10 g) was heated to 180° C. for 90 min. The hot mixture was poured into water (100 ml), basified with 50% aqueous solution of sodium hydroxide and extracted with dichloromethane (3×100 ml). The combined extracts were washed with water (100 ml) and brine (100 ml), dried (magnesium sulfate) and concentrated to dryness. Purification by column chromatography (silica gel, 300 g; n-hexane/ethyl acetate (7/3)) yielded 0.61 g (13%) of the titled compound as red solids. 1H-NMR (CDCl3) δ: 9.53 (1H, br.s), 8.72-8.67 (1H, m), 7.95 (1H ddd, J=7.7, 7.7, 1.8 Hz), 7.60-7.49 (3H, m), 7.43-7.31 (3H, m), 7.23-7.14 (3H, m), 7.09-7.04 (1H, m), 2.63 (3H, br.s)

1. extractionextracted with dichloromethane (3×100 ml)
2. washThe combined extracts were washed with water (100 ml) and brine (100 ml)
3. dry with materialdried (magnesium sulfate)
4. concentrationconcentrated to dryness
5. customPurification by column chromatography (silica gel, 300 g; n-hexane/ethyl acetate (7/3))