Potassium Hydroxide → 4-Butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acid

HRID 348985

Reaction equation

HRID 348985 reaction equation
[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:17]([O:19]C)=[O:18])[CH:13]=[C:14]([C:15]#[N:16])[C:9]=2[O:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4].[OH-].[K+]>CO.O>[CH2:1]([N:5]1[C:10]2[CH:11]=[C:12]([C:17]([OH:19])=[O:18])[CH:13]=[C:14]([C:15]#[N:16])[C:9]=2[O:8][CH2:7][CH2:6]1)[CH2:2][CH2:3][CH3:4]

Participants

5

Reactant 2

HCID 14797Potassium HydroxideHCID 21086202Methyl 4-butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Product 1

HCID 210859314-Butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylic acidYield 88.2%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Procedure

To a stirred solution of Methyl 4-butyl-8-cyano-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (184 mg) in methanol (3 mL) was added potassium hydroxide (7 mL of a 1.0 M solution in water). The mixture was stirred at room temperature overnight then 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 (4×100 mL). The combined organic extracts were dried (sodium sulfate), filtered, and concentrated under reduced pressure to give 154 mg of the title compound: 1H NMR (300 MHz, CDCl3) (57.62, 7.46, 4.44, 3.41, 3.33, 1.60, 1.41, 0.98.

Workup

  1. concentrationthen concentrated under reduced pressure
  2. additionThe residue was diluted with water
  3. washwashed with ethyl acetate
  4. extractionextracted with chloroform (4×100 mL)
  5. dry with materialThe combined organic extracts were dried (sodium sulfate)
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-a6f17698ccba43aaa558f4226778b18a
Source dataset
uspto-grants-2007_02
Patent number
US07176242B2

Linked notes

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