Triethylamine → (NE)-N-[(7-bromo-2-methyl-1,3-benzoxazol-4-yl)methylidene]hydroxylamine

HRID 1505254Notes

Reaction equation

HRID 1505254 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]([CH:12]=O)=[C:6]2[C:10]=1[O:9][C:8]([CH3:11])=[N:7]2.Cl.[NH2:15][OH:16].C(N(CC)CC)C>CO.O.C(OCC)(=O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5](/[CH:12]=[N:15]/[OH:16])=[C:6]2[C:10]=1[O:9][C:8]([CH3:11])=[N:7]2

Participants

7

Reactant 3

HCID 8471TriethylamineHCID 443297Hydroxyamine hydrochlorideHCID 584979577-Bromo-2-methyl-benzo[d]oxazole-4-carbaldehyde

Product 1

HCID 58498024(NE)-N-[(7-bromo-2-methyl-1,3-benzoxazol-4-yl)methylidene]hydroxylamineYield 105.2%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 962WaterSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

To a suspension of 7-bromo-2-methyl-benzo[d]oxazole-4-carbaldehyde (Example 6.6) (3.23 g) in a mixture of methanol and water (7:3) (60 ml) were added successively hydroxylamine hydrochloride (1.03 g) and triethylamine (2.06 ml) and the reaction mixture was stirred at ambient temperature for 1 hour. The reaction mixture was diluted with ethyl acetate (200 ml) and water (200 ml). The phases were separated and the aqueous phase was extracted with ethyl acetate (150 ml). The combined organic extracts were washed with brine (200 ml), dried over sodium sulfate and concentrated to give (E)-7-bromo-2-methyl-benzo[d]oxazole-4-carbaldehyde oxime (3.61 g) as a brown solid. 1H-NMR (400 MHz, CDCl3): 9.47 (s, 1H) 7.47 (d, 1H), 7.33 (d, 1H), 2.74 (s, 3H) ppm.

Workup

  1. customThe phases were separated
  2. extractionthe aqueous phase was extracted with ethyl acetate (150 ml)
  3. washThe combined organic extracts were washed with brine (200 ml)
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-340ac04f04fd41feb3e63f11045d1917
Source dataset
uspto-grants-2015_12
Patent number
US09216973B2

Reaction notes

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