Acetic Anhydride → 4-Benzoylamino-1-hexyn-5-one

HRID 1755946Notes

Reaction equation

HRID 1755946 reaction equation
C(O[C:5](=[O:7])[CH3:6])(=O)C.[C:8]([NH:16][CH:17]([CH2:21][C:22]#[CH:23])C(O)=O)(=[O:15])[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1>N1C=CC=CC=1.O>[C:8]([NH:16][CH:17]([C:5](=[O:7])[CH3:6])[CH2:21][C:22]#[CH:23])(=[O:15])[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 199184862-Benzamidopent-4-ynoic acid

Product 1

HCID 106324564-Benzoylamino-1-hexyn-5-one

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 1049PyridineSolvent

Conditions

Temperature
90 °C

Procedure

Acetic anhydride (150 ml) was added to a solution of 2-benzoylamino-4-pentynoic acid (J. Org. Chem. 1983, 48, 3318) (73 g, 0.34 mol) in pyridine (200 ml) and the solution was heated to 90° C. for 1 hour, then allowed to cool to 60° C. and water (150 ml) was added. The mixture was heated to 85°-90° C. for 20 minutes, then cooled, diluted with water (300 ml) and extracted with chloroform (2×400 ml). The combined extracts were washed with water, 1N hydrochloric acid (3×500 ml), sodium bicarbonate and brine, and dried over magnesium sulfate. The chloroform solution was decolorized with charcoal, filtered and concentrated. The residue was recrystallized from butyl chloride to yield a tan solid (51 g, mp 101°-103° C.).

Workup

  1. temperatureto cool to 60° C.
  2. temperatureThe mixture was heated to 85°-90° C. for 20 minutes
  3. temperaturecooled
  4. extractionextracted with chloroform (2×400 ml)
  5. washThe combined extracts were washed with water, 1N hydrochloric acid (3×500 ml), sodium bicarbonate and brine
  6. dry with materialdried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customThe residue was recrystallized from butyl chloride

Sources & evidence

ORD record
ord-41b8768da973474881d3a8a3949d1dc8
Source dataset
uspto-grants-1995_08
Patent number
US05438074

Reaction notes

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