反应详情

60 g (0.39 mol) 4-chloro-2,3,5-trimethylpyridine and 21.7 g (0.40 mol) sodium methoxide and 180 ml dry dimethylsulfoxide was heated with stirring to 55°-60° C. for 8 hrs. The reaction mixture was diluted with 600 ml water and extracted with 3x100 ml toluene and the organic layer washed with 2x50 ml water. The organic phase was added to 200 ml water and pH adjusted to 4.1 with stirring. This process was repeated twice with 200 ml and 100 ml of water. The organic layer contained almost pure starting material. The combined water phase was made alkaline and extracted with 2×150 ml methylene chloride. Evaporation of solvent gave 40.7 g of almost pure 4-methoxy-2,3,5-trimethylpyridine. NMR: 2×3H, 2,2: 3H, 2,45(s); 3H, 3,75(s); 1H, 8,2(s). (CDCl3)

1. extractionextracted with 3x100 ml toluene
2. washthe organic layer washed with 2x50 ml water
3. additionThe organic phase was added to 200 ml water
4. stirringwith stirring
5. extractionextracted with 2×150 ml methylene chloride
6. customEvaporation of solvent