Hydrochloric Acid → 2-(4-Hydroxy-3-methyl-benzofuran-2-yl)-oxazole-4-carboxylic acid ethyl ester

HRID 843150Notes

Reaction equation

HRID 843150 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[N:7]=[C:8]([C:11]2[O:12][C:13]3[CH:20]=[CH:19][CH:18]=[C:17]([O:21]CC=C)[C:14]=3[C:15]=2[CH3:16])[O:9][CH:10]=1)=[O:5])[CH3:2].C1N2CCN(CC2)C1.Cl>C(O)C.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Cl-].[Rh]>[CH2:1]([O:3][C:4]([C:6]1[N:7]=[C:8]([C:11]2[O:12][C:13]3[CH:20]=[CH:19][CH:18]=[C:17]([OH:21])[C:14]=3[C:15]=2[CH3:16])[O:9][CH:10]=1)=[O:5])[CH3:2]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 9237DabcoHCID 54249963HCID 54249963, compound

Product 1

HCID 1360886772-(4-Hydroxy-3-methyl-benzofuran-2-yl)-oxazole-4-carboxylic acid ethyl esterYield 81.5%

Reagents, catalysts & solvents 2

HCID 84599Chlorotris(triphenylphosphine)rhodium(I)CatalystHCID 702EthanolSolvent

Procedure

2-(4-Allyloxy-3-methyl-benzofuran-2-yl)-oxazole-4-carboxylic acid ethyl ester (671 mg) in 80% aqueous ethanol (60 ml) was stirred in the presence of chlorotris(triphenylphosphine)rhodium (63 mg) and triethylenediamine (32 mg) at 90° C. for 6 hours. The reaction mixture was poured into 1N aqueous hydrochloric acid and extracted with ethyl acetate. The combined organic extracts were washed with brine and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure gave 2-(4-hydroxy-3-methyl-benzofuran-2-yl)-oxazole-4-carboxylic acid ethyl ester as a white solid (480 mg). EI-MS: m/z 287 (M+).

Workup

  1. extractionextracted with ethyl acetate
  2. washThe combined organic extracts were washed with brine
  3. dry with materialdried over magnesium sulfate
  4. customEvaporation of the solvent under reduced pressure

Sources & evidence

ORD record
ord-91392153f8b84f62a4c3a709ae8d8175
Source dataset
uspto-grants-2002_04
Patent number
US06376491B1

Reaction notes

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