4-methoxy-2-n-propylpyridine-N-oxide → 4-Methoxy-2-n-propylpyridine

HRID 1421261Notes

Reaction equation

HRID 1421261 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][N+:6]([O-])=[C:5]([CH2:10][CH2:11][CH3:12])[CH:4]=1>S(=O)(=O)(O)O.[Zn]>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][N:6]=[C:5]([CH2:10][CH2:11][CH3:12])[CH:4]=1

Participants

4

Reactant 1

HCID 187069924-methoxy-2-n-propylpyridine-N-oxide

Product 1

HCID 110840544-Methoxy-2-n-propylpyridineYield 86%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 1118Sulfuric AcidSolvent

Conditions

Temperature
75 °C

Procedure

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 with sodium sulfate, filtered and evaporated to a yellow oil. Distillation (0.1-0.2 mbar, 44-46° C.) afforded 46.1 g (86%) of 4-methoxy-2-n-propylpyridine as a colourless oil. 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).

Workup

  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 with sodium sulfate
  8. filtrationfiltered
  9. customevaporated to a yellow oil
  10. distillationDistillation (0.1-0.2 mbar, 44-46° C.)

Sources & evidence

ORD record
ord-983f4b85a4c94a6e873248f98cfebcb3
Source dataset
uspto-grants-2000_06
Patent number
US06075036

Reaction notes

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