反应详情

温度

100 °C

3.0 g of 5-bromo-2,3-diaminopyridine (S.-X. Cai et al., J. Med. Chem. 1997, 40(22), 3679-3686) in 120 g of polyphosphoric acid are heated at 160° C. for 0.5 h. The solution is cooled to 100° C. and 1.26 ml of chloroacetonitrile are added. Thereafter, the reaction mixture is heated to 170° C. for 22 h. After cooling, the polyphosphoric acid is hydrolysed with 81 ml of water. After reheating to 90° C., charcoal is added under vigorous stirring. Subsequently, the suspension is filtered through a celite pad while still hot (70° C.). The filter cake is rinsed with 85 ml of water. The filtrate is adjusted to pH 4 using 9.0 M aqueous sodium hydroxide solution. The precipitate is collected, suspended in 100 ml of hot methanol and filtered over celite. The filtrate is concentrated to dryness to afford 2.78 g of the title compound as a beige, amorphous solid of m.p. >325° C. MS: 246.2/248.2/250.3 (MH+, 77%/100%/25%). TLC: Rf=0.42 (dichloromethane/methanol 10:1 parts by volume).

1. temperatureThereafter, the reaction mixture is heated to 170° C. for 22 h
2. temperatureAfter cooling
3. customAfter reheating to 90° C.
4. filtrationSubsequently, the suspension is filtered through a celite pad while still hot (70° C.)
5. washThe filter cake is rinsed with 85 ml of water
6. customThe precipitate is collected
7. filtrationfiltered over celite
8. concentrationThe filtrate is concentrated to dryness