Dimethylformamide → 3-Chloro-5-methoxybenzaldehyde

HRID 1827666Notes

Reaction equation

HRID 1827666 reaction equation
Cl[C:2]1[CH:3]=[C:4]([O:9][CH3:10])[CH:5]=[C:6]([Cl:8])[CH:7]=1.[Mg].CN(C)[CH:14]=[O:15]>C1COCC1.BrCCBr>[Cl:8][C:6]1[CH:7]=[C:2]([CH:3]=[C:4]([O:9][CH3:10])[CH:5]=1)[CH:14]=[O:15]

Participants

6

Reactant 3

HCID 6228DimethylformamideHCID 365883,5-DichloroanisoleHCID 5462224Magnesium

Product 1

HCID 219046333-Chloro-5-methoxybenzaldehydeYield 54%

Reagents, catalysts & solvents 2

HCID 78391,2-DibromoethaneCatalystHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

3,5-Dichloroanisole (74.0 g, 419 mmol) in THF (200 mL) was added dropwise to magnesium metal (14.2 g, 585 mmol, pre-washed with 0.5 N HCl) in THF (100 mL) at 25° C. After the addition, 1,2-dibromoethane (3.9 g, 20.8 mmol) was added dropwise. The resultant dark brown mixture was heated at reflux for 3 h. The mixture was cooled to 0° C., and N,N-dimethylformamide (60 mL) was added in one portion. The mixture was partitioned with diethyl ether (3×400 mL) and 6N HCl (500 mL). The combined organic extracts were washed with brine (300 mL), dried (Na2SO4), filtered and concentrated in vacuo to give an oil. Flash chromatography (2×) on silica get eluting with Hex:EtOAc (4:1) afforded the sub-title compound (38.9 g, 54%) as a yellow oil.

Workup

  1. additionwas added dropwise
  2. temperatureThe resultant dark brown mixture was heated
  3. temperatureat reflux for 3 h
  4. customThe mixture was partitioned with diethyl ether (3×400 mL) and 6N HCl (500 mL)
  5. washThe combined organic extracts were washed with brine (300 mL)
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. customto give an oil
  10. customFlash chromatography (2×) on silica get
  11. washeluting with Hex

Sources & evidence

ORD record
ord-70c4bdc8af284e91a39219a996e7bf29
Source dataset
uspto-grants-2006_06
Patent number
US07056907B2

Reaction notes

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