反应详情

温度

75 °C

A solution of 4-methoxy-2-n-propylpyridine-N-oxide (59.3 g, 0.355 mol) in 800 ml of 1 M sulfuric acid was stirred and heated to 70-80° C. Zinc dust (140.0 g, 214 mol) was added in portions over four hours. When the addition was complete, heating was continued for a further eight hours. The resulting precipitate was filtered off and washed with water. The filtrate was made strongly alkaline by addition of a 32% sodium hydroxide solution and extracted with dichloromethane (3×250 ml). The extracts were combined, dried over sodium sulfate, filtered, evaporated and distilled. This gave 46.1 g (86%) of 4-methoxy-2-n-propylpyridine as a colourless oil. B.p. 44-46° C./0.1-0.2 mbar. 1H-NMR (CDCl3, 200 MHz) δ: 0.99 (t, 3H); 1.75 (sext, 2H); 2.72 (t, 2H); 3.81 (s, 3H); 6.10-6.18 (m, 2H); 8.35 (d, 1H).

1. additionWhen the addition
2. temperatureheating
3. filtrationThe resulting precipitate was filtered off
4. washwashed with water
5. additionThe filtrate was made strongly alkaline by addition of a 32% sodium hydroxide solution
6. extractionextracted with dichloromethane (3×250 ml)
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. customevaporated
10. distillationdistilled