Hydrochloric Acid → 4,5-Dimethyl-2-naphthalen-2-yloxazole 3-oxide

HRID 1373157Notes

Reaction equation

HRID 1373157 reaction equation
[CH3:1]/[C:2](/[C:5]([CH3:7])=[O:6])=[N:3]\[OH:4].[CH:8]1[C:17]2[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=2)[CH:11]=[CH:10][C:9]=1[CH:18]=O.Cl>C(O)(=O)C>[CH3:1][C:2]1[N+:3]([O-:4])=[C:18]([C:9]2[CH:10]=[CH:11][C:12]3[C:17](=[CH:16][CH:15]=[CH:14][CH:13]=3)[CH:8]=2)[O:6][C:5]=1[CH3:7]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 62012-NaphthalenecarboxaldehydeHCID 64096332,3-Butanedione monoxime

Product 1

HCID 210742674,5-Dimethyl-2-naphthalen-2-yloxazole 3-oxide

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

18.4 g of diacetyl monoxime and 31.2 g of 2-naphthaldehyde are added to 50 ml of glacial acetic acid, and HCl gas is introduced with ice-cooling for 30 minutes. 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 a mixture of dichloromethane and water, and a basic pH is established using ammonia. The mixture is extracted three times with in each case 500 ml of dichloromethane and ethyl acetate, the combined organic phases are dried over MgSO4 and the solvent is then removed under reduced pressure. This gives 40.3 g of 4,5-dimethyl-2-naphthalen-2-yloxazole 3-oxide as a yellow solid.

Workup

  1. additionis introduced with ice-
  2. temperaturecooling for 30 minutes
  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. additionThe precipitate is suspended in a mixture of dichloromethane and water
  7. extractionThe mixture is extracted three times with in each case 500 ml of dichloromethane and ethyl acetate
  8. dry with materialthe combined organic phases are dried over MgSO4
  9. customthe solvent is then removed under reduced pressure

Sources & evidence

ORD record
ord-58023a4e004549509c086967483353d8
Source dataset
uspto-grants-2007_01
Patent number
US07160911B2

Reaction notes

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