Acetic Anhydride → 7-Acetoxy-6-methoxy-3,4-dihydroquinazolin-4-one

HRID 634676Notes

Reaction equation

HRID 634676 reaction equation
[CH2:1]([O:8][C:9]1[CH:18]=[C:17]2[C:12]([C:13](=[O:19])[NH:14][CH:15]=[N:16]2)=[CH:11][C:10]=1[O:20][CH3:21])[C:2]1C=CC=CC=1.C(OC(=O)C)(=[O:24])C.C([O-])(=O)C.[Na+]>[Pd].C1(C)C=CC=CC=1>[C:1]([O:8][C:9]1[CH:18]=[C:17]2[C:12]([C:13](=[O:19])[NH:14][CH:15]=[N:16]2)=[CH:11][C:10]=1[O:20][CH3:21])(=[O:24])[CH3:2]

Participants

6

Reactant 3

HCID 7918Acetic AnhydrideHCID 517045Sodium AcetateHCID 1354047187-Benzyloxy-6-methoxy-3H-quinazolin-4-one

Product 1

HCID 1356979057-Acetoxy-6-methoxy-3,4-dihydroquinazolin-4-oneYield 27%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 1140TolueneSolvent

Procedure

A mixture of 7-benzyloxy-6-methoxy-3,4-dihydroquinazolin-4-one (5.0 g, mmol), (prepared as described for the starting material in Example 4), acetic anhydride (200 ml), sodium acetate (12 g), 10% palladium-on-charcoal catalyst (1.5 g) in toluene (100 ml) was stirred under an atmosphere of hydrogen for 3 hours. The mixture was filtered and the filtrate was evaporated. The residue was partitioned between a mixture of ethyl acetate (500 ml), methanol (20 ml) and water (300 ml). The organic phase was separated, dried (MgSO4) and the solvent removed by evaporation. The residue was triturated with hexane to give 7-acetoxy-6-methoxy-3,4-dihydroquinazolin-4-one (1.1 g, 27%).

Workup

  1. custom(prepared
  2. filtrationThe mixture was filtered
  3. customthe filtrate was evaporated
  4. customThe residue was partitioned between a mixture of ethyl acetate (500 ml), methanol (20 ml) and water (300 ml)
  5. customThe organic phase was separated
  6. dry with materialdried (MgSO4)
  7. customthe solvent removed by evaporation
  8. customThe residue was triturated with hexane

Sources & evidence

ORD record
ord-f7eb46552a89414f888a53c4538981a0
Source dataset
uspto-grants-2001_02
Patent number
US06184225B2

Reaction notes

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