2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 3-(4-Methyl-benzooxazol-2-yl)-benzoic acid methyl ester

HRID 1694365Notes

Reaction equation

HRID 1694365 reaction equation
[NH2:1][C:2]1[C:7]([CH3:8])=[CH:6][CH:5]=[CH:4][C:3]=1[OH:9].[CH3:10][O:11][C:12](=[O:21])[C:13]1[CH:18]=[CH:17][CH:16]=[C:15]([CH:19]=O)[CH:14]=1.C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N.C([O-])(O)=O.[Na+]>CO.C(Cl)Cl.CCOC(C)=O>[CH3:10][O:11][C:12](=[O:21])[C:13]1[CH:18]=[CH:17][CH:16]=[C:15]([C:19]2[O:9][C:3]3[CH:4]=[CH:5][CH:6]=[C:7]([CH3:8])[C:2]=3[N:1]=2)[CH:14]=1

Participants

8

Reactant 4

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 516892Sodium BicarbonateHCID 639145Methyl 3-formylbenzoateHCID 30141382-Amino-m-cresol

Product 1

HCID 672798453-(4-Methyl-benzooxazol-2-yl)-benzoic acid methyl ester

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

2-Amino-3-methyl-phenol (6.09 mmol) is heated with 3-formyl-benzoic acid methyl ester (6.09 mmol) in MeOH (6 mL) at 60° C. for 30 minutes. The solvent is removed from the mixture to obtain a dark red oil which is dissolved in dry CH2Cl2 (6 mL) at room temperature and treated with DDQ (6.4 mmol) for 16 hours. The mixture is diluted with EtOAc and poured onto saturated aqueous NaHCO3. The aqueous phase is further extracted with EtOAc and the combined organic phases are dried over Na2 SO4. Filtration and removal of the solvent yields a residue which is purified by silica gel chromatography (5-10% EtOAc/hexane) to yield 3-(4-methyl-benzooxazol-2-yl)-benzoic acid methyl ester as a white solid: 1H NMR (400 MHz, CDCl3) 8.92 (d, J=1.6 Hz, 1H), 8.47 (dt, J1=7.8 Hz, J2=1.5 Hz, 1H), 8.2 (dt, J1=7.8 Hz, J2=1.4 Hz, 1H), 7.61 (t, J=7.9 Hz, 1H), 7.43 (d, J=8.1 Hz, 1H), 7.27 (t, J=7.7 Hz, 1H), 7.17 (t, J=7.5 Hz, 1H), 3.99 (s, 3H), 2.69 (s, 3H); LC/MS (ES+): (M+1) 268.1.

Workup

  1. customThe solvent is removed from the mixture
  2. customto obtain a dark red oil which
  3. extractionThe aqueous phase is further extracted with EtOAc
  4. customthe combined organic phases are dried over Na2 SO4
  5. filtrationFiltration and removal of the solvent
  6. customyields a residue which
  7. customis purified by silica gel chromatography (5-10% EtOAc/hexane)

Sources & evidence

ORD record
ord-3b0c51842989482fa19d04cc3654383b
Source dataset
uspto-grants-2012_04
Patent number
US08158662B2

Reaction notes

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