反应详情

139.5 g. of 4,6-dichloro-2-methyl-5-nitropyridine-3-carboxylic acid ethyl ester (0.5 Mol.) are dissolved in about 500 ml. of methanol. 60 g. of triethylamine are added and the solution is heated at reflux temperature. At this point, 36.5 g. of n-butylamine are added dropwise. The solvent is then removed in vacuo and 500 ml. of benzene are added to the residue. The triethylamine hydrochloride is filtered off and the solvent evaporated. The resulting oil is dissolved in 300 ml. of methanol and yields on cooling 110 g. of 4-butylamino-6-chloro-2-methyl-2-nitropyridine-3-carboxylic acid, ethyl ester (70%), m.p. 33°-35° (methanol).

1. temperaturethe solution is heated
2. temperatureat reflux temperature
3. customThe solvent is then removed in vacuo and 500 ml
4. additionof benzene are added to the residue
5. filtrationThe triethylamine hydrochloride is filtered off
6. customthe solvent evaporated
7. dissolutionThe resulting oil is dissolved in 300 ml
8. customof methanol and yields
9. temperatureon cooling 110 g