Dimethylformamide → 2-Fluoro-4,6-dihydroxybenzaldehyde

HRID 322988Notes

Reaction equation

HRID 322988 reaction equation
CN(C)[CH:3]=[O:4].P(Cl)(Cl)(Cl)=O.[OH:11][C:12]1[CH:13]=[C:14]([F:19])[CH:15]=[C:16]([OH:18])[CH:17]=1>O>[OH:11][C:12]1[CH:17]=[C:16]([OH:18])[CH:15]=[C:14]([F:19])[C:13]=1[CH:3]=[O:4]

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24813Phosphorus oxychlorideHCID 126587785-Fluororesorcinol

Product 1

HCID 220104032-Fluoro-4,6-dihydroxybenzaldehydeYield 27.4%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Dimethylformamide (DMF) (12.7 g) is added to vigorously stirred phosphorous oxychloride (14.4 g) at 0° C. The reaction mixture is stirred at this temperature for 30 minutes, then 3,5-dihydroxyfluorobenzene (6 g) is added. The sticky red syrup is allowed to warm to room temperature and stirred for 2 hours, then left to stand for 14 hours. Water (100 mL) is added and the mixture extracted three times with ethyl acetate (100 mL). The combined organic phases are washed with brine (100 mL), dried over magnesium sulphate and evaporated. The residue is purified by flash chromatography on silica eluting with a mixture of ethyl acetate and pentane (1:2 v/v). Fractions homogeneous in the required product are combined and evaporated to give an orange solid which is triturated with ethyl acetate to give 2,4-dihydroxy-6-fluorobenzaldehyde (2 g) as a yellow solid.

Workup

  1. stirringstirred for 2 hours
  2. waitleft
  3. waitto stand for 14 hours
  4. extractionthe mixture extracted three times with ethyl acetate (100 mL)
  5. washThe combined organic phases are washed with brine (100 mL)
  6. dry with materialdried over magnesium sulphate
  7. customevaporated
  8. customThe residue is purified by flash chromatography on silica eluting with a mixture of ethyl acetate and pentane (1:2 v/v)
  9. customevaporated
  10. customto give an orange solid which
  11. customis triturated with ethyl acetate

Sources & evidence

ORD record
ord-312112656329475f994fa2bcd5a49e4c
Source dataset
uspto-grants-2001_04
Patent number
US06211234B1

Reaction notes

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