Hydrochloric Acid → 2,2,9-Trimethyl-2H-pyrano[2,3-g]quinoline

HRID 2425338Notes

Reaction equation

HRID 2425338 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][C:7]([CH3:13])([CH3:12])[CH:6]=[CH:5]2.[CH3:14][C:15]([CH:17]=[CH2:18])=O.[N+](C1C=C(S(O)(=O)=O)C=CC=1)([O-])=O.Cl>C(O)C.[Cl-].[Zn+2].[Cl-]>[CH3:12][C:7]1([CH3:13])[O:8][C:9]2=[CH:10][C:11]3[C:17]([CH3:18])=[CH:15][CH:14]=[N:1][C:2]=3[CH:3]=[C:4]2[CH:5]=[CH:6]1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 6570Methyl vinyl ketoneHCID 73873-Nitrobenzenesulfonic acidHCID 100808812,2-Dimethyl-2H-chromen-6-amine

Product 1

HCID 591344012,2,9-Trimethyl-2H-pyrano[2,3-g]quinolineYield 38%

Reagents, catalysts & solvents 2

HCID 3007855ZincchlorideCatalystHCID 702EthanolSolvent2×

Conditions

Temperature
110 °C

Procedure

To a solution of 6-amino-2,2-dimethylchromene (10.1 g, 57.7 mmol) in ethanol (500 mL), methylvinylketone (33.0 mL, 404 mmol), m-nitrobenzenesulfonic acid (21.1 g, 104 mmol), zinc chloride (1.97 g, 14.4 mmol) and 35% hydrochloric acid (24 mL, 289 mmol) were added at room temperature and the resulting mixture was stirred at 110° C. for 5 hours. Upon the completion of the reaction, ethanol was distilled off, water was added, and the resulting solution was neutralized with sodium hydrogencarbonate and extracted with ethyl acetate. The resulting organic phase was washed with sodium chloride aqueous solution, and dried over anhydrous magnesium sulfate. After distilling off the solvent, the residue was purified by medium pressure column chromatography (hexane/ethyl acetate=3/1) and the aimed product was obtained (yield: 38%).

Workup

  1. distillationwas distilled off
  2. additionwater was added
  3. extractionextracted with ethyl acetate
  4. washThe resulting organic phase was washed with sodium chloride aqueous solution
  5. dry with materialdried over anhydrous magnesium sulfate
  6. distillationAfter distilling off the solvent
  7. customthe residue was purified by medium pressure column chromatography (hexane/ethyl acetate=3/1)

Sources & evidence

ORD record
ord-55a39da3ab604a218549c99a0796ee3c
Source dataset
uspto-grants-2011_06
Patent number
US07964623B2

Reaction notes

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