Potassium Carbonate → 2,2-dimethyl-3,4-dihydro-2H-1,4-benzoxazin-3-one

HRID 72562Notes

Reaction equation

HRID 72562 reaction equation
Br[C:2]([CH3:14])([CH3:13])[C:3]([NH:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[OH:12])=[O:4].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[CH3:13][C:2]1([CH3:14])[C:3](=[O:4])[NH:5][C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[O:12]1

Participants

4

Reactant 2

HCID 11430Potassium CarbonateHCID 146849852-bromo-N-(2-hydroxyphenyl)-2-methylpropionamide

Product 1

HCID 106073952,2-dimethyl-3,4-dihydro-2H-1,4-benzoxazin-3-oneYield 84.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

To a stirred solution of 2-Bromo-N-(2-hydroxy-phenyl)-2-methyl-propionamide (21.8 g, 84.4 mmol) in DMF (85 mL) at 25° C. was added potassium carbonate (23.32 g, 168.99 mmol) and stirred the reaction mixture at 80° C. for 4 h. After TLC reaction mixture was filtered through celite and diluted with ethyl acetate 500 mL and then washed with water (100 mL×3), brine (100 mL), dried over anhydrous sodium sulfate, concentrated to give 2,2-dimethyl-4H-benzo[1,4]oxazin-3-one (12.64 g) as brown solid which was purified by column chromatography to furnish 8.5 g pure compound.

Workup

  1. filtrationAfter TLC reaction mixture was filtered through celite
  2. additiondiluted with ethyl acetate 500 mL
  3. washwashed with water (100 mL×3), brine (100 mL)
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-310676b3b0374acb974741ad049f92f7
Source dataset
uspto-grants-2014_09
Patent number
US08828951B2

Reaction notes

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