Ethyl 2-(2-benzoylhydrazinyl)-2-oxoacetate → Ethyl 5-phenyl-1,3,4-oxadiazole-2-carboxylate

HRID 1178103Notes

Reaction equation

HRID 1178103 reaction equation
[CH2:1]([O:3][C:4](=[O:17])[C:5]([NH:7][NH:8][C:9](=[O:16])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=O)[CH3:2]>O=P(Cl)(Cl)Cl>[CH2:1]([O:3][C:4]([C:5]1[O:16][C:9]([C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)=[N:8][N:7]=1)=[O:17])[CH3:2]

Participants

3

Reactant 1

HCID 13013233Ethyl 2-(2-benzoylhydrazinyl)-2-oxoacetate

Product 1

HCID 651752Ethyl 5-phenyl-1,3,4-oxadiazole-2-carboxylateYield 96.2%

Reagents, catalysts & solvents 1

HCID 24813Phosphorus oxychlorideSolvent

Procedure

A solution of (N′-benzoyl-hydrazino)-oxo-acetic acid ethyl ester (508 mg, 2.15 mmol) in POCl3 (4 mL) was heated to reflux for 3 hrs. The reaction mixture was then concentrated under reduced pressure to remove POCl3 and the resulting residue was dissolved in ethyl acetate. Subsequently, the ethyl acetate layer was washed with water and brine solution, dried over sodium sulphate and concentrated under reduced pressure to afford 450 mg (96.2% yield) of 5-phenyl[1,3,4]oxadiazole-2-carboxylic acid ethyl ester as off white solid. LCMS purity: 93.86%

Workup

  1. temperatureto reflux for 3 hrs
  2. concentrationThe reaction mixture was then concentrated under reduced pressure
  3. customto remove POCl3
  4. dissolutionthe resulting residue was dissolved in ethyl acetate
  5. washSubsequently, the ethyl acetate layer was washed with water and brine solution
  6. dry with materialdried over sodium sulphate
  7. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-9f3eff46249643e1bf5bbe1b2d0621a7
Source dataset
uspto-grants-2010_11
Patent number
US07842696B2

Reaction notes

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