Potassium Carbonate → (E)-3-(benzooxazol-4-yloxy)-but-2-enoic acid ethyl ester

HRID 19388

Reaction equation

HRID 19388 reaction equation
[O:1]1[C:5]2=[CH:6][CH:7]=[CH:8][C:9]([OH:10])=[C:4]2[N:3]=[CH:2]1.[CH2:11]([O:13][C:14](=[O:18])[C:15]#[C:16][CH3:17])[CH3:12].C(=O)([O-])[O-].[K+].[K+]>CN(C)C1C=CN=CC=1.O1CCCC1>[CH2:11]([O:13][C:14](=[O:18])/[CH:15]=[C:16](/[O:10][C:9]1[C:4]2[N:3]=[CH:2][O:1][C:5]=2[CH:6]=[CH:7][CH:8]=1)\[CH3:17])[CH3:12]

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 78043Ethyl 2-butynoateHCID 137206971,3-Benzoxazol-4-ol

Product 1

HCID 66895566(E)-3-(benzooxazol-4-yloxy)-but-2-enoic acid ethyl esterYield 100.1%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
80 °C

Procedure

A stirred mixture of benzooxazol-4-ol (0.388 g, 2.87 mmol), ethyl-2-butynoate (1.93 g, 17.2 mmol) a catalytic amount of 4-dimethylaminopyridine and potassium carbonate (0.595 g, 4.30 mmol) in tetrahydrofuran (20 mL) was placed in a sealed tube and heated at 80° C. for 2 h. The reaction mixture was filtered and the filtrate was collected and concentrated in vacuo. The resulting residue was purified by ISCO column chromatography (Silicycle 40 g, 2% to 15% ethyl acetate/hexanes) which afforded (E)-3-(benzooxazol-4-yloxy)-but-2-enoic acid ethyl ester (710 mg, 100%) as a light yellow solid.

Workup

  1. customwas placed in a sealed tube
  2. filtrationThe reaction mixture was filtered
  3. customthe filtrate was collected
  4. concentrationconcentrated in vacuo
  5. customThe resulting residue was purified by ISCO column chromatography (Silicycle 40 g, 2% to 15% ethyl acetate/hexanes) which

Sources & evidence

ORD record
ord-a6e7976868214a29b3b7aa30f68365d0
Source dataset
uspto-grants-2010_06
Patent number
US07741327B2

Linked notes

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