2,6-Dichlorobenzaldehyde → 2-(2,6-Dichlorophenyl)-benzooxazole-6-carboxylic acid methyl ester

HRID 1514969Notes

Reaction equation

HRID 1514969 reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([NH2:10])=[C:6]([OH:11])[CH:5]=1.[Cl:13][C:14]1[CH:21]=[CH:20][CH:19]=[C:18]([Cl:22])[C:15]=1[CH:16]=O>CO>[CH3:1][O:2][C:3]([C:4]1[CH:9]=[CH:8][C:7]2[N:10]=[C:16]([C:15]3[C:14]([Cl:13])=[CH:21][CH:20]=[CH:19][C:18]=3[Cl:22])[O:11][C:6]=2[CH:5]=1)=[O:12]

Participants

4

Reactant 2

HCID 67372,6-DichlorobenzaldehydeHCID 7020619Benzoic acid, 4-amino-3-hydroxy-, methyl ester

Product 1

HCID 669656572-(2,6-Dichlorophenyl)-benzooxazole-6-carboxylic acid methyl ester

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
45 °C

Procedure

To a solution of 4-amino-3-hydroxy-benzoic acid methyl ester (2.0 g) in MeOH (100 mL) was added 2,6-dichlorobenzaldehyde (2.1 g). The reaction mixture was heated at 45° C. overnight, and then concentrated in vacuo. The residue was dissolved in THF (10 mL) and dichloromethane (90 mL). To the mixture solution was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (2.72 g). The reaction mixture was stirred for 1 h, diluted with NaHCO3 aqueous solution, extracted with EtOAc, and washed with brine. The extracts were dried over Na2SO4 and concentrated in vacuo. Purification by column chromatography (SiO2, 2:3 EtOAc/Hexane) gave 2-(2,6-dichlorophenyl)-benzooxazole-6-carboxylic acid methyl ester: MS (m/z) 321.9 (M+1).

Workup

  1. concentrationconcentrated in vacuo
  2. dissolutionThe residue was dissolved in THF (10 mL)
  3. additionTo the mixture solution was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (2.72 g)
  4. additiondiluted with NaHCO3 aqueous solution
  5. extractionextracted with EtOAc
  6. washwashed with brine
  7. dry with materialThe extracts were dried over Na2SO4
  8. concentrationconcentrated in vacuo
  9. customPurification by column chromatography (SiO2, 2:3 EtOAc/Hexane)

Sources & evidence

ORD record
ord-d91573f5724d429b84abfffb62fafef0
Source dataset
uspto-grants-2012_07
Patent number
US08222248B2

Reaction notes

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