反应详情

Peracetic acid (40%, 5.0 ml) is added to 4-(3-chloropropyl)pyridine (5.18 g) at such a rate as to keep the reaction temperature at 80°. The mixture is stirred until the temperature falls to 30°. Excess peracid is destroyed with sodium sulfite solution and the solvent is vacuum distilled. The residue is redissolved in methylene chloride (50 ml), filtered and evaporated to yield and crude 4-(3-chloropropyl)-pyridine-N-oxide which is heated to 80° in dimethyl sulfate (4.66 g) for 2 hours. The resulting 4-(3-chloropropyl)-1-methoxypyridinium methyl sulfate salt is dissolved in 10 ml of water, cooled to 0° and reacted with an ice-cold solution of potassium cyanide (6.7 g, 100 mmol) in 20 ml of 0.25N sodium hydroxide solution for 22 hours. The product is extracted with methylene chloride (3×30 ml) and dried over sodium sulfate. The solvent is evaporated and the residue filtered through 45 g of silica gel with ether to yield 4-(3-chloropropyl)-2-cyanopyridine; NMR (CDCl3) 3.56 (t, 2H), 7.40 (d, 1H), 7.57 (s, 1H), 8.60 (d, 1H).

1. customat 80°
2. customfalls to 30°
3. customExcess peracid is destroyed with sodium sulfite solution
4. distillationdistilled
5. dissolutionThe residue is redissolved in methylene chloride (50 ml)
6. filtrationfiltered
7. customevaporated
8. customto yield
9. temperaturecooled to 0°
10. extractionThe product is extracted with methylene chloride (3×30 ml)
11. dry with materialdried over sodium sulfate
12. customThe solvent is evaporated
13. filtrationthe residue filtered through 45 g of silica gel with ether