Acetic Anhydride → 4-Acetoxy-6-s-butyl-8-formyl-2,3-dimethylquinoline

HRID 1840243Notes

Reaction equation

HRID 1840243 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[C:7]([CH:16]=[O:17])[CH:8]=[C:9]([CH:12]([CH2:14][CH3:15])[CH3:13])[CH:10]=2)[N:5]=[C:4]([CH3:18])[C:3]=1[CH3:19].C(=O)([O-])O.[Na+].[C:25](OC(=O)C)(=[O:27])[CH3:26]>N1C=CC=CC=1>[C:25]([O:1][C:2]1[C:11]2[C:6](=[C:7]([CH:16]=[O:17])[CH:8]=[C:9]([CH:12]([CH2:14][CH3:15])[CH3:13])[CH:10]=2)[N:5]=[C:4]([CH3:18])[C:3]=1[CH3:19])(=[O:27])[CH3:26]

Participants

5

Reactant 3

HCID 7918Acetic AnhydrideHCID 516892Sodium BicarbonateHCID 178441048HCID 178441048, compound

Product 1

HCID 220525424-Acetoxy-6-s-butyl-8-formyl-2,3-dimethylquinolineYield 13%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Conditions

Temperature
120 °C

Procedure

800 Milligrams of the resultant 4-benzyloxy-6-s-butyl-8-formyl-2,3-dimethylquinoline was dissolved in 2.5 ml of 20% sulfuric acid and stirred at 100° C. for 1 hour. After cooling to room temperature, the reaction mixture was neutralized with an aqueous saturated sodium hydrogencarbonate solution to produce precipitates, which were washed with water and n-hexane and then dried under reduced pressure to obtain 490 mg of 4-hydroxy-6-s-butyl-8-formyl-2,3-dimethylquinoline. 440 Milligrams of 4-hydroxy-6-s-butyl-8-formyl-2,3-dimethylquinoline was suspended in a mixture of 3 ml of acetic anhydride and 0.5 ml of pyridine and the mixture was stirred at 120° C. for 1.5 hours. The reaction mixture was cooled to room temperature, neutralized with an aqueous saturated sodium hydrogencarbonate solution and extracted with ethyl acetate. The resultant organic layer was washed with a saturated brine and dried over anhydrous sodium sulfate. After the solvent was evaporated, the resultant crude product was purified by column chromatography on silica gel (WAKOGEL® C-200) eluting with n-hexane/ethyl acetate (10:1) to obtain 220 mg of 4-acetoxy-6-s-butyl-8-formyl-2,3-dimethylquinoline (yield 13%). Its NMR spectral data are shown in the following Table 2.

Workup

  1. temperatureThe reaction mixture was cooled to room temperature
  2. extractionextracted with ethyl acetate
  3. washThe resultant organic layer was washed with a saturated brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. customAfter the solvent was evaporated
  6. customthe resultant crude product was purified by column chromatography on silica gel (WAKOGEL® C-200)
  7. washeluting with n-hexane/ethyl acetate (10:1)

Sources & evidence

ORD record
ord-bdea67ebff8b4398837a235868633656
Source dataset
uspto-grants-2004_01
Patent number
US06680282B2

Reaction notes

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