Hydrochloric Acid → 2-(4-methoxyphenyl)-4,5-dimethyloxazole N-oxide

HRID 2233554Notes

Reaction equation

HRID 2233554 reaction equation
[CH3:1]/[C:2](/[C:5]([CH3:7])=[O:6])=[N:3]\[OH:4].[CH3:8][O:9][C:10]1[CH:17]=[CH:16][C:13]([CH:14]=O)=[CH:12][CH:11]=1.Cl>C(O)(=O)C>[CH3:8][O:9][C:10]1[CH:17]=[CH:16][C:13]([C:14]2[O:6][C:5]([CH3:7])=[C:2]([CH3:1])[N+:3]=2[O-:4])=[CH:12][CH:11]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 312444-MethoxybenzaldehydeHCID 64096332,3-Butanedione monoxime

Product 1

HCID 200640242-(4-methoxyphenyl)-4,5-dimethyloxazole N-oxide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

50.6 g of Diacetylmonoxime and 66.7 ml of 4-methoxy-benzaldehyde are added to 100 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 82.1 g of 2-(4-methoxy-phenyl)-4,5-dimethyl-oxazole 3-oxide as a white solid. C12H13NO3 (219.24), MS (ESI)=220 (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-3b3bf5e33c1640ee9aa3de86c568ad6b
Source dataset
uspto-grants-2010_05
Patent number
US07709509B2

Reaction notes

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