Hydrochloric Acid → 7-(Benzyloxy)-4-methyl-2H-chromene

HRID 217425Notes

Reaction equation

HRID 217425 reaction equation
[CH2:1]([O:8][C:9]1[CH:18]=[C:17]2[C:12]([C:13](=O)[CH2:14][CH2:15][O:16]2)=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:20][Mg]Br.[NH4+].[Cl-].Cl>C1COCC1>[CH2:1]([O:8][C:9]1[CH:18]=[C:17]2[C:12]([C:13]([CH3:20])=[CH:14][CH2:15][O:16]2)=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 25517Ammonium ChlorideHCID 45218987-(benzyloxy)-3,4-dihydro-2H-1-benzopyran-4-oneHCID 178418573HCID 178418573, compound2×

Product 1

HCID 584387087-(Benzyloxy)-4-methyl-2H-chromene

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

7-(benzyloxy)-2,3-dihydro-4H-chromen-4-one was dissolved in THF, a solution (0.97 M, 5 mL) of methylmagnesium bromide in THF was added dropwise thereto at 0° C., followed by stirring at room temperature for 1 hour, and a solution (0.97 M, 5 mL) of methylmagnesium bromide in THF was added dropwise thereto, followed by stirring at room temperature for 2 hours. To the reaction liquid was added a saturated aqueous NH4Cl solution and subsequently 2 M hydrochloric acid (20 mL), followed by stirring at room temperature for 2 hours and then extracting with EtOAc three times. The organic layer was combined, washed with water and brine, dried over MgSO4, and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (automatic purification device, hexane:EtOAc=95:5 to 90:10) to obtain 7-(benzyloxy)-4-methyl 2H-chromene (445 mg) as a colorless transparent liquid.

Workup

  1. customat 0° C.
  2. stirringby stirring at room temperature for 2 hours
  3. customTo the reaction liquid
  4. stirringby stirring at room temperature for 2 hours
  5. extractionextracting with EtOAc three times
  6. washwashed with water and brine
  7. dry with materialdried over MgSO4
  8. concentrationconcentrated under reduced pressure
  9. customThe residue was purified by silica gel column chromatography (automatic purification device, hexane:EtOAc=95:5 to 90:10)

Sources & evidence

ORD record
ord-efe7b9a6971a47059481d8a847ed0fa9
Source dataset
uspto-grants-2012_06
Patent number
US08193378B2

Reaction notes

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