反应详情

温度

50 °C

1-Cyano-4-(N,N-dimethylamino)-1-ethoxycarbonyl-2-methyl-1,3-butadiene (25.0 g, 0.12 mol) prepared in a manner analogous to that described in Example (i) above in toluene (250 ml) was heated to 50° C. for 3 hours with stirring whereupon a steady stream of hydrogen chloride was passed through the reaction mixture. After cooling, the mixture was washed with water (250 ml). The aqueous layer was then extracted with toluene (3×100 ml). The pooled organic layers were dried with sodium sulphate and evaporated. Distillation of the residue in high vacuo yielded 2-chloro-4-methylnicotinic acid ethyl ester as colourless oil (15.3 g, 64% of theoretical yield) with b.pt.0.04 Torr 97° C.-98° C.

1. temperatureAfter cooling
2. washthe mixture was washed with water (250 ml)
3. extractionThe aqueous layer was then extracted with toluene (3×100 ml)
4. dry with materialThe pooled organic layers were dried with sodium sulphate
5. customevaporated
6. distillationDistillation of the residue in high vacuo
7. customyielded