Hydrochloric Acid → 4-Methyl-5-phenyl-2-p-tolyloxazole 3-oxide

HRID 854617Notes

Reaction equation

HRID 854617 reaction equation
[C:1]1([C:7](=[O:12])[C:8](=[N:10][OH:11])[CH3:9])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[C:13]1([CH3:21])[CH:18]=[CH:17][C:16]([CH:19]=O)=[CH:15][CH:14]=1.Cl>C(O)(=O)C>[CH3:9][C:8]1[N+:10]([O-:11])=[C:21]([C:13]2[CH:18]=[CH:17][C:16]([CH3:19])=[CH:15][CH:14]=2)[O:12][C:7]=1[C:1]1[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 77254-MethylbenzaldehydeHCID 63990241,2-Propanedione, 1-phenyl-, 2-oxime

Product 1

HCID 589341914-Methyl-5-phenyl-2-p-tolyloxazole 3-oxide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

12.5 g of 1-phenyl-1,2-propanedione-2-oxime and 10 ml of p-tolualdehyde are added to 50 ml of glacial acetic acid, and HCl gas is introduced for 30 minutes, with ice-cooling. The product is precipitated as the hydrochloride by addition of methyl tert-butyl ether and filtered off with suction, and the precipitate is washed with methyl tert-butyl ether. The precipitate is suspended in water and the pH is made alkaline using ammonia. The mixture is extracted three times with in each case 200 ml of dichloromethane, the combined organic phases are dried over MgSO4 and the solvent is then removed under reduced pressure. This gives 6.4 g of 4-methyl-5-phenyl-2-p-tolyloxazole 3-oxide as a white solid. C17H15NO2 (265.31), MS (ESI)=266 (M+H+).

Workup

  1. additionis introduced for 30 minutes, with ice-
  2. temperaturecooling
  3. customThe product is precipitated as the hydrochloride by addition of methyl tert-butyl ether
  4. filtrationfiltered off with suction
  5. washthe precipitate is washed with methyl tert-butyl ether
  6. extractionThe mixture is extracted three times with in each case 200 ml of dichloromethane
  7. dry with materialthe combined organic phases are dried over MgSO4
  8. customthe solvent is then removed under reduced pressure

Sources & evidence

ORD record
ord-78d9d1f2189c403db31e258d5cbfbb57
Source dataset
uspto-grants-2007_08
Patent number
US07259177B2

Reaction notes

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