反应详情

6-Quinoxalinecarboxylic acid (320 mg; 1.8 mmol) is suspended in 10 ml methylene chloride. As the suspension is stirred, 2 equivalents of triethylamine are added, followed by 0.22 ml (1.8 mmol) of trimethylacetyl chloride. After 15 min, 164 ul (1.8 mmol) of 1,2,3,6-tetrahydropyridine is added and the solution is stirred overnight. The solution is diluted with 20 ml of diethyl ether and washed with 10 ml water followed by 10 ml 10% NaCO3. The organic solution is dried over Na2SO4/K2CO3 and concentrated to a red-brown oil. Purification by chromatography on silica gel (eluted with CCl4/CHCl3 1:1) gives a pale yellow oil that eventually solidifies. The solid is layered with hexane and finely dispersed by mechanical crushing to yield pale yellow XIII. EMIS m/z=239 (parent), 157 (base), and 129. 1H NMR δ 2.22 and 2.34 (br, 2), 3.54, 3.94, 3.97, and 4.29 (br, 4), 5.5-6.0 (br, 2), 7.85 (dd, 1, J=8.7, 1.3 Hz), 8.15 (d, 1, J=1.6 Hz), 8.18 (br d, 1, J=8.5 Hz), and 8.90 ppm (s, 1).

1. stirringthe solution is stirred overnight
2. washwashed with 10 ml water
3. dry with materialThe organic solution is dried over Na2SO4/K2CO3
4. concentrationconcentrated to a red-brown oil
5. customPurification by chromatography on silica gel (eluted with CCl4/CHCl3 1:1)
6. customgives a pale yellow oil that
7. additionfinely dispersed
8. customby mechanical crushing