反应详情

温度

140 °C

With stirring, a mixture of 8.06 g of 3-(4-methoxypyridin-2-yl)propionic acid (starting material B1), 9.5 g of 2,3-diamino-5-iodopyridine (Cugola et al., Bioorg.Med. Chem.Let 22, 2749-2754 (1996)) and 150 g of polyphosphoric acid (PPA) is heated at 140° C. for 22 hours. After cooling, the mixture is poured into about 1000 ml of ice-water and then neutralized (pH 7-8) using 6N aqueous sodium hydroxide solution. The mixture is extracted four times with ethyl acetate and the combined organic phases are evaporated to dryness. The residue is crystallized first from ethyl acetate and then from methanol, giving 9.4 g of the title compound as a light-beige powder of m.p. 207-208° C.; the mass spectrum shows the molecular peak MH+ at 381.2 Da.

1. temperatureAfter cooling
2. extractionThe mixture is extracted four times with ethyl acetate
3. customthe combined organic phases are evaporated to dryness
4. customThe residue is crystallized first from ethyl acetate