Hydrochloric Acid → 3-Fluoro-4,5-dihydroxybenzaldehyde

HRID 253300Notes

Reaction equation

HRID 253300 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].[F:5][C:6]1[CH:7]=[C:8]([CH:11]=[C:12]([O:15]C)[C:13]=1[OH:14])[CH:9]=[O:10].N1C=CC=CC=1.Cl>ClCCl>[F:5][C:6]1[CH:7]=[C:8]([CH:11]=[C:12]([OH:15])[C:13]=1[OH:14])[CH:9]=[O:10]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 5984523-Fluoro-4-hydroxy-5-methoxybenzaldehydeHCID 6451240Aluminum(III) Chloride

Product 1

HCID 5936643-Fluoro-4,5-dihydroxybenzaldehydeYield 85.2%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Anhydrous aluminum chloride (1.11 g, 8.2 mmol) was added to a solution of 3-fluoro-4-hydroxy-5-methoxy benzaldehyde (1.2 g; 6.8 mmol) in dry dichloromethane (16 ml) under an atmosphere of nitrogen. The reaction mixture was cooled down to 0° C., pyridine (2.5 ml; 31 mmol) was slowly added and the solution was heated to reflux and stirred for 24 h. The solution was cooled to 0° C. and 4M aqueous hydrochloric acid was added to the mixture until the pH was approximately 2. The organic phase was discarded and the water phase was extracted with ethyl ether (3×15 ml). The organic extracts were combined then dried over sodium sulfate and concentrated under vacuum to give 3-fluoro-4,5-dihydroxybenzaldehyde (0.904 g; 85% yield) as a yellow solid. 1H NMR (400 MHz, CD3OD) δ 9.68 (d, 1H), 7.17 (dd, 1H), 7.16 (br. s, 1H). MS (EI) for C7H5FO3: 157 (MH+).

Workup

  1. temperaturethe solution was heated
  2. temperatureto reflux
  3. temperatureThe solution was cooled to 0° C.
  4. extractionthe water phase was extracted with ethyl ether (3×15 ml)
  5. dry with materialThe organic extracts were combined then dried over sodium sulfate
  6. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-fd0e96b9f1fd4b87854c17a7e1ecb387
Source dataset
uspto-grants-2011_01
Patent number
US07872014B2

Reaction notes

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