反应详情

27.9 g. of 4,6-dichloro-2-methyl-5-nitropyridine-3-carboxylic acid ethyl ester (0.1 mol.) are dissolved in 100 ml. of ethyl alcohol and 12 g. of triethylamine. At reflux temperature a solution of 4.5 g. of ethylamine in 50 ml. of alcohol is slowly added dropwise with continual stirring. After the addition is completed, the reaction mixture is refluxed for an additional 30 minutes. The solvent is then removed in vacuo and the residue is dissolved in 300 ml. of petroleum ether. The triethylamine hydrochloride is filtered off and the filtrate cooled to 0°; 6-chloro-4-ethylamino-2-methyl-5-nitropyridine-3-carboxylic acid ethyl ester crystallizes, yield: 69%, m.p. 36°-37° (methanol).

1. temperatureAt reflux temperature a solution of 4.5 g
2. additionAfter the addition
3. temperaturethe reaction mixture is refluxed for an additional 30 minutes
4. customThe solvent is then removed in vacuo
5. dissolutionthe residue is dissolved in 300 ml
6. filtrationThe triethylamine hydrochloride is filtered off
7. temperaturethe filtrate cooled to 0°
8. custom6-chloro-4-ethylamino-2-methyl-5-nitropyridine-3-carboxylic acid ethyl ester crystallizes