Pyridine → 3,4-Dihydroxy-5-nitrobenzaldehyde

HRID 1880435Notes

Reaction equation

HRID 1880435 reaction equation
[OH:1][C:2]1[C:9]([N+:10]([O-:12])=[O:11])=[CH:8][C:5]([CH:6]=[O:7])=[CH:4][C:3]=1[O:13]C.[Cl-].[Al+3].[Cl-].[Cl-].N1C=CC=CC=1>CCOC(C)=O>[OH:13][C:3]1[CH:4]=[C:5]([CH:8]=[C:9]([N+:10]([O-:12])=[O:11])[C:2]=1[OH:1])[CH:6]=[O:7]

Participants

5

Reactant 3

HCID 1049PyridineHCID 811345-NitrovanillinHCID 6451240Aluminum(III) Chloride

Product 1

HCID 57489573,4-Dihydroxy-5-nitrobenzaldehydeYield 67.6%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
60 °C

Procedure

To a vigorously stirred suspension of 4-hydroxy-3-methoxy-5-nitrobenzaldehyde (47.0 g, 238 mmol) in EtOAc (450 mL) at room temperature, anhydrous aluminum chloride (38.1 g, 286 mmol) was added in one portion. Then pyridine (77 mL, 954 mmol) was added dropwise at 45-50° C. for 30 minutes. The reaction mixture was refluxed for 2 hours and allowed to cool down to 60° C. The reaction mixture was carefully poured into ice/concentrated HCl mixture (265 mL). After stirring at 50° C. for 1 hour, the reaction mixture was cooled to 0° C. The formed precipitate was separated by filtration, washed with water, and vacuum-dried to afford 3,4-dihydroxy-5-nitrobenzaldehyde (29.4 g, 161 mmol, 67.3% yield).

Workup

  1. temperatureThe reaction mixture was refluxed for 2 hours
  2. temperaturethe reaction mixture was cooled to 0° C
  3. customThe formed precipitate was separated by filtration
  4. washwashed with water
  5. customvacuum-dried

Sources & evidence

ORD record
ord-716e1ee2b32148c3b4e9d52611aea233
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

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