Potassium Hydroxide → 4-Butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acid

HRID 14219Notes

Reaction equation

HRID 14219 reaction equation
[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:15]([O:17]C)=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4].[OH-].[K+]>CO>[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:15]([OH:17])=[O:16])[CH:13]=[CH:14][C:9]=2[O:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4]

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 21086198Methyl 4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Product 1

HCID 210859294-Butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acidYield 98.8%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a stirred solution of methyl 4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (412 mg) in methanol (5 mL) was added 1 M potassium hydroxide (17 mL). The mixture was stirred at room temperature for 5 h and concentrated under reduced pressure. The residue was diluted with water and washed with ethyl acetate. The aqueous layer was acidified to pH 4 with 1 N hydrochloric acid and extracted with chloroform (4×50 mL). The combined organic extracts were dried (sodium sulfate), filtered, and concentrated under reduced pressure to provide 384 mg of the title compound: ESI MS m/z 236 [M+H]+.

Workup

  1. concentrationconcentrated under reduced pressure
  2. additionThe residue was diluted with water
  3. washwashed with ethyl acetate
  4. extractionextracted with chloroform (4×50 mL)
  5. dry with materialThe combined organic extracts were dried (sodium sulfate)
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-d8a57acb98734333a79adcd0cc6e2fed
Source dataset
uspto-grants-2010_06
Patent number
US07727997B2

Reaction notes

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