Oxazole → 3-(Methoxycarbonyl)-5-(1,3-oxazol-2-yl)benzoic Acid

HRID 14118

Reaction equation

HRID 14118 reaction equation
[O:1]1[CH:5]=[CH:4][N:3]=[CH:2]1.C([Li])CCC.I[C:12]1[CH:13]=[C:14]([CH:18]=[C:19]([C:21]([O:23][CH3:24])=[O:22])[CH:20]=1)[C:15]([OH:17])=[O:16]>O1CCCC1.[Cl-].[Zn+2].[Cl-]>[CH3:24][O:23][C:21]([C:19]1[CH:18]=[C:14]([CH:13]=[C:12]([C:2]2[O:1][CH:5]=[CH:4][N:3]=2)[CH:20]=1)[C:15]([OH:17])=[O:16])=[O:22]

Participants

6

Conditions

Temperature
0 °C

Procedure

To a −70° C. stirred solution of oxazole (432 mg, 6.3 mmol) in tetrahydrofuran (10 mL) is added n-butyllithium (2.5 M in hexanes, 2.75 mL, 6.9 mmol). After 30 min, zinc chloride (1 M in diethyl ether, 18.75 mL, 18.75 mmol) is added and the reaction mixture is warmed to 0° C. for 1 h. To this mixture is added a solution of 3-iodo-5-(methoxycarbonyl)benzoic acid prepared by the method in Example SP-281, step 1 (1.8 g, 6 mmol) in anhydrous tetrahydrofuran (10 mL) followed by palladium(0)tetrakis(triphenylphosphine) (291 mg, 0.25 mmol). The reaction mixture is heated at reflux for 15 h. The reaction mixture is cooled, filtered through diatomaceous earth, diluted with ethyl acetate (50 mL), washed with water, and brine, dried (sodium sulfate), filtered, and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, 5% methanol/methylene chloride) provides the title compound in pure form. ESI MS m/z 246.1 [M−H]−.

Workup

  1. temperatureThe reaction mixture is heated
  2. temperatureat reflux for 15 h
  3. temperatureThe reaction mixture is cooled
  4. filtrationfiltered through diatomaceous earth
  5. additiondiluted with ethyl acetate (50 mL)
  6. washwashed with water, and brine
  7. dry with materialdried (sodium sulfate)
  8. filtrationfiltered
  9. concentrationconcentrated under reduced pressure
  10. customPurification by flash column chromatography (silica gel, 5% methanol/methylene chloride)

Sources & evidence

ORD record
ord-5300a9569b4c4d14bd3a9b5cc261602e
Source dataset
uspto-grants-2010_06
Patent number
US07727997B2

Linked notes

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