反应详情

温度

120 °C

A mixture of methyl 3-aminocrotonate (5 g) and 5-(1-hydroxypropylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (10 g) (obtained as described in J. Org. Chem., 1978, 43, 2087) was heated at 120° C. for 1 hour. The residue was cooled to ambient temperature and treated with a mixture of ether and hexane (1:6 v/v; 35 ml) and allowed to stand for 18 hours. The solvent was removed by decanting and the insoluble residue purified by flash chromatography, eluting with methanol/dichloromethane (1:9 v/v) to give methyl 1,4-dihydro-6-ethyl-2-methyl-4-oxopyridine-3-carboxylate (1 g), as a yellow solid, m.p. 176°-180° C.; NMR (CDCl3): 1.2(t,3H); 2.45(s,3H), 2.65(q,2H), 3.8(s,3H), 6.3(s,1H); mass spectrum (chemical ionisation, ammonia): 196(M+H)+.

1. temperatureThe residue was cooled to ambient temperature
2. customThe solvent was removed
3. customby decanting
4. customthe insoluble residue purified by flash chromatography
5. washeluting with methanol/dichloromethane (1:9 v/v)