Hydrochloric Acid → 4-Chloro-2-methyl-1-oxo-1lambda~5~-pyridine

HRID 1525835Notes

Reaction equation

HRID 1525835 reaction equation
[CH3:1][C:2]1[CH:7]=[C:6]([N+]([O-])=O)[CH:5]=[CH:4][N+:3]=1[O-:11].[ClH:12]>>[Cl:12][C:6]1[CH:5]=[CH:4][N+:3]([O-:11])=[C:2]([CH3:1])[CH:7]=1

Participants

3

Reactant 2

HCID 313Hydrochloric AcidHCID 95291Pyridine, 2-methyl-4-nitro-, 1-oxide

Product 1

HCID 122118014-Chloro-2-methyl-1-oxo-1lambda~5~-pyridineYield 75%

Procedure

2-methyl-4-nitropyridine 1-oxide (5.0 g, 32 mmol, 1.0 eq) was dissolved in concentrated HCl (80 mL) and refluxed for 3 days. The reaction was cooled and the excess concentrated HCl was removed in vacuo. The viscous oil was neutralized with 10% K2CO3 and extracted with CH2Cl2 (5×). The combined organics were dried (MgSO4), filtered, and concentrated in vacuo. Purification by flash chromatography on silica gel afforded 3.49 g (75%) of the title compound as a yellow solid. 1H NMR (400 MHz, DMSO-d6) δ 8.23 (d, J=7.0 Hz, 1H), 7.66 (d, J=3.0 Hz, 1H), 7.40 (dd, J=7.0, 3.0 Hz, 1H), 2.32 (s, 3H); ES-MS [M+1]+: 144.2.

Workup

  1. temperaturerefluxed for 3 days
  2. temperatureThe reaction was cooled
  3. customthe excess concentrated HCl was removed in vacuo
  4. extractionextracted with CH2Cl2 (5×)
  5. dry with materialThe combined organics were dried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customPurification by flash chromatography on silica gel

Sources & evidence

ORD record
ord-63a367e7c01b49afbf66b172f994b868
Source dataset
uspto-grants-2015_07
Patent number
US09085562B2

Reaction notes

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