Potassium Carbonate → 8-Bromo-2-methyl-3,4-dihydro-2H-1,4-benzoxazin-3-one

HRID 2175221Notes

Reaction equation

HRID 2175221 reaction equation
Br[CH:2]([CH3:14])[C:3]([NH:5][C:6]1[CH:11]=[CH:10][CH:9]=[C:8]([Br:12])[C:7]=1[OH:13])=[O:4].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C.O>[Br:12][C:8]1[C:7]2[O:13][CH:2]([CH3:14])[C:3](=[O:4])[NH:5][C:6]=2[CH:11]=[CH:10][CH:9]=1

Participants

5

Reactant 2

HCID 11430Potassium CarbonateHCID 672670902-Bromo-N-(3-bromo-2-hydroxyphenyl)propionamide

Product 1

HCID 672673248-Bromo-2-methyl-3,4-dihydro-2H-1,4-benzoxazin-3-oneYield 95%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

A mixture of 2-bromo-N-(3-bromo-2-hydroxyphenyl)propanamide (4.72 g, 14.61 mmol) and potassium carbonate (2.020 g, 14.61 mmol) in DMF (50 mL) was stirred at room temperature overnight. At the conclusion of this period, the reaction mixture was diluted with water and extracted with ether. The organic layer was dried over anhydrous MgSO4, filtered, and concentrated. The resulting residue was purified by flash chromatography (100:0:0 to 0:90:10 hexanes:ethyl acetate:methanol) to afford the title compound (3.35 g, 95% yield) as a brown solid. 1H NMR (400 MHz, CDCl3) δ 8.17 (br. S, 1H), 7.22 (dd, J=8.0, 1.4 Hz, 1H), 6.85 (t, J=7.9 Hz, 1H), 6.76 (dd, J=7.8, 1.4 Hz, 1H), 4.78 (q, J=6.8 Hz, 1H), 1.64 (d, J=6.8 Hz, 3H).

Workup

  1. extractionextracted with ether
  2. dry with materialThe organic layer was dried over anhydrous MgSO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe resulting residue was purified by flash chromatography (100:0:0 to 0:90:10 hexanes:ethyl acetate:methanol)

Sources & evidence

ORD record
ord-4f561ad4d02c4f3a8a98a9c07ebe99a5
Source dataset
uspto-grants-2015_06
Patent number
US09062028B2

Reaction notes

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