Acetic Anhydride → 1,2-Dimethyl-1H-imidazo[4,5-c]pyridine

HRID 1467701Notes

Reaction equation

HRID 1467701 reaction equation
[CH3:1][NH:2][C:3]1[CH:8]=[CH:7][N:6]=[CH:5][C:4]=1[NH2:9].[C:10](OC(=O)C)(=O)[CH3:11]>>[CH3:1][N:2]1[C:3]2[CH:8]=[CH:7][N:6]=[CH:5][C:4]=2[N:9]=[C:10]1[CH3:11]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 9104124-N-methylpyridine-3,4-diamine

Product 1

HCID 42873941,2-Dimethyl-1H-imidazo[4,5-c]pyridineYield 64%

Procedure

The solution of N4-methylpyridine-3,4-diamine (2.5 g, 20.3 mmol) in acetic anhydride (25 mL) was refluxed overnight. Then acetic anhydride was evaporated under reduced pressure and 1 N hydrochloride acid was added. Then the mixture was extracted with dichloromethane (50 mL×3). The aqueous layer was neutralized with sodium bicarbonate, and extracted with dichloromethane (50 mL×3). The organic layers were concentrated to give the title compound (1.9 g, yield 64%). LC-MS (ESI) m/z: 148 (M+1)+. 1H-NMR (400 MHz, CDCl3) δ (ppm): 2.64 (s, 3H), 3.74 (s, 3H), 7.23-7.24 (d, J=5.2 Hz, 1H), 8.39-8.41 (d, J=5.2 Hz, 1H), 8.98 (s, 1H).

Workup

  1. customThen acetic anhydride was evaporated under reduced pressure and 1 N hydrochloride acid
  2. additionwas added
  3. extractionThen the mixture was extracted with dichloromethane (50 mL×3)
  4. extractionextracted with dichloromethane (50 mL×3)
  5. concentrationThe organic layers were concentrated

Sources & evidence

ORD record
ord-e56d2d43789d423cbb8791e7b772a124
Source dataset
uspto-grants-2015_04
Patent number
US08999987B2

Reaction notes

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