Acetic Anhydride → 7-Methyl-2-(2-oxopropyl)-4H-3,1-benzoxazin-4-one

HRID 597212Notes

Reaction equation

HRID 597212 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([NH2:11])[C:5](=[CH:9][CH:10]=1)[C:6]([OH:8])=[O:7].[CH2:12]=[C:13]1[O:17][C:15](=O)[CH2:14]1.C(OC(=O)C)(=O)C>C(Cl)(Cl)(Cl)Cl>[CH2:14]([C:15]1[O:7][C:6](=[O:8])[C:5]2[CH:9]=[CH:10][C:2]([CH3:1])=[CH:3][C:4]=2[N:11]=1)[C:13]([CH3:12])=[O:17]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 12661DiketeneHCID 753164-Methylanthranilic acid

Product 1

HCID 214470767-Methyl-2-(2-oxopropyl)-4H-3,1-benzoxazin-4-oneYield 48%

Reagents, catalysts & solvents 1

HCID 5943Carbon TetrachlorideSolvent

Procedure

A mixture of 4-methylanthranilic acid (25.0 g., 0.17 mole) and diketene (13.95 g., 0.17 mole) in CCl4 (250 ml.) was heated at reflux for 2.5 hours. Acetic anhydride (18.3 g., 0.18 mole) was added and the mixture was stirred under reflux for 16 hours. The mixture then was cooled and the product isolated by filtration; upon recrystallization there was obtained 2-acetonyl-7-methyl-4H-3,1-benzoxazin-4-one (17.4 g., 48 percent), mp 142°-144° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 2.5 hours
  3. temperatureunder reflux for 16 hours
  4. temperatureThe mixture then was cooled
  5. customthe product isolated by filtration
  6. customupon recrystallization there

Sources & evidence

ORD record
ord-f9e0a85d801c405cbdc21ec4474f8cf1
Source dataset
uspto-grants-1977_03
Patent number
US04013665

Reaction notes

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