Diethyl Oxalate → 8-methyl-4-oxo-7-(phenylmethoxy)-4H-1-benzopyran-2-carboxylic acid

HRID 23331Notes

Reaction equation

HRID 23331 reaction equation
[OH:1][C:2]1[C:7]([CH3:8])=[C:6]([O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH:5]=[CH:4][C:3]=1[C:17](=[O:19])[CH3:18].[C:20](OCC)(=O)[C:21]([O:23]CC)=[O:22].C[O-].[Na+]>C1(C)C=CC=CC=1>[CH3:8][C:7]1[C:2]2[O:1][C:20]([C:21]([OH:23])=[O:22])=[CH:18][C:17](=[O:19])[C:3]=2[CH:4]=[CH:5][C:6]=1[O:9][CH2:10][C:11]1[CH:12]=[CH:13][CH:14]=[CH:15][CH:16]=1

Participants

5

Reactant 3

HCID 7268Diethyl OxalateHCID 7361854'-Benzyloxy-2'-hydroxy-3'-methylacetophenoneHCID 10942334Sodium Methoxide

Product 1

HCID 225732428-methyl-4-oxo-7-(phenylmethoxy)-4H-1-benzopyran-2-carboxylic acidYield 95.4%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

A mixture of 1-[2-hydroxy-3-methyl-4-(phenylmethoxy)phenyl]-ethanone (0.098 mol) and ethanedioic acid, diethyl ester (0.11 mol) in toluene (100 ml) was added dropwise to a mixture of sodium methoxide (0.22 mol) in toluene (150 ml). The reaction mixture was stirred and refluxed for 2 hours. The solvent was evaporated. The residue was added to a mixture of acetic acid (150 ml) and hydrochloric acid (50 ml). The reaction mixture was stirred and refluxed for 1 hour. The mixture was poured out onto ice. The resulting precipitate was filtered off and dried (vacuum; 70° C.), yielding 29 g (95.4%) of 8-methyl-4-oxo-7-(phenylmethoxy)-4H-1-benzopyran-2-carboxylic acid (interm. 9).

Workup

  1. temperaturerefluxed for 2 hours
  2. customThe solvent was evaporated
  3. additionThe residue was added to a mixture of acetic acid (150 ml) and hydrochloric acid (50 ml)
  4. stirringThe reaction mixture was stirred
  5. temperaturerefluxed for 1 hour
  6. additionThe mixture was poured out onto ice
  7. filtrationThe resulting precipitate was filtered off
  8. customdried (vacuum; 70° C.)

Sources & evidence

ORD record
ord-b6e11d698b0b4e43a46330c8a8509f06
Source dataset
uspto-grants-2005_02
Patent number
US06852714B2

Reaction notes

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