Sodium hydride → 2-(3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazin-4-yl)pyridine N-oxide

HRID 1197763

Reaction equation

HRID 1197763 reaction equation
[H-].[Na+].[CH3:3][C:4]1([CH3:17])[CH2:9][NH:8][C:7]2[CH:10]=[CH:11][C:12]([N+:14]([O-:16])=[O:15])=[CH:13][C:6]=2[O:5]1.Cl.Br[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][N+:21]=1[O-:26]>CN(C)C=O>[CH3:3][C:4]1([CH3:17])[CH2:9][N:8]([C:20]2[CH:25]=[CH:24][CH:23]=[CH:22][N+:21]=2[O-:26])[C:7]2[CH:10]=[CH:11][C:12]([N+:14]([O-:16])=[O:15])=[CH:13][C:6]=2[O:5]1

Participants

5

Reactant 3

HCID 24758Sodium hydrideHCID 27240442-Bromopyridine 1-oxide hydrochlorideHCID 104885702,2-Dimethyl-7-nitro-3,4-dihydro-2H-benzo[B][1,4]oxazine

Product 1

HCID 105661912-(3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazin-4-yl)pyridine N-oxideYield 23.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

To a suspension of 0.38 g sodium hydride (60% in paraffin composition) in 14 ml dimethylformamide, was added 1.00 g 3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazine, and 1.01 g 2-bromopyridine N-oxide hydrochloride was further added under ice-cooling, and the mixture was stirred for 16 hours at 70° C. The reaction mixture was poured to ice water, the resulting mixture was extracted with ethyl acetate, and the extract was washed with an aqueous solution of sodium chloride and dried over anhydrous magnesium sulfate. The solvent was distilled off from the dried solution under reduced pressure, the residue was subjected to column chromatography on silica gel, and elution was conducted by the use of a 3:1 mixture of chloroform and acetone, thus giving 0.34 g of 2-(3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazin-4-yl)pyridine N-oxide. Ethanolic solution of hydrogen chloride (a mixture of 1 ml concentrated hydrochloric acid and 5 ml ethanol) was then added to the product obtained above, the solvent was distilled off from the mixture, and the residue was recrystallized from acetone, thus giving 182 mg of 2-(3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazin-4-yl)pyridine N-oxide hydrochloride.

Workup

  1. additionwas further added under ice-
  2. temperaturecooling
  3. extractionthe resulting mixture was extracted with ethyl acetate
  4. washthe extract was washed with an aqueous solution of sodium chloride
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationThe solvent was distilled off from the dried solution under reduced pressure
  7. washthe residue was subjected to column chromatography on silica gel, and elution
  8. additionwas conducted by the use of a 3:1 mixture of chloroform and acetone

Sources & evidence

ORD record
ord-d2e82f3fbc884c37aecafc5235c8fad4
Source dataset
uspto-grants-1994_01
Patent number
US05278158

Linked notes

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