Pyridine → (2E)-3-(2,6-dimethoxyphenyl)acrylonitrile

HRID 1040327Notes

Reaction equation

HRID 1040327 reaction equation
[N:1]1C=CC=[CH:3][CH:2]=1.C(CC(O)=O)#N.[CH3:13][O:14][C:15]1[CH:22]=[CH:21][CH:20]=[C:19]([O:23][CH3:24])[C:16]=1[CH:17]=O>C1(C)C=CC=CC=1.C([O-])(=O)C.[NH4+]>[CH3:13][O:14][C:15]1[CH:22]=[CH:21][CH:20]=[C:19]([O:23][CH3:24])[C:16]=1/[CH:17]=[CH:3]/[C:2]#[N:1]

Participants

6

Reactant 3

HCID 1049PyridineHCID 9740Cyanoacetic acidHCID 964042,6-Dimethoxybenzaldehyde

Product 1

HCID 59658521(2E)-3-(2,6-dimethoxyphenyl)acrylonitrileYield 89.3%

Reagents, catalysts & solvents 2

HCID 517165Ammonium AcetateCatalystHCID 1140TolueneSolvent

Procedure

Add, one after another, 1.13 g (14.7 mmol) of ammonium acetate, 40.4 mL (500 mmol) of pyridine and 31.2 g (367 mmol) of 2-cyanoacetic acid to a solution of 61 g (367 mmol) of 2,6-dimethoxybenzaldehyde in 360 mL of toluene. Reflux the reaction mixture for 15 h, distilling the toluene-water azeotrope in Dean-Stark apparatus. Take up the solution in 500 mL toluene and 40 mL pyridine and reflux again for 48 h in the Dean-Stark apparatus. After concentration under reduced pressure, take up the residue in 800 mL of dichloromethane (DCM) and wash successively with 1 L of 1N HCl aqueous solution, 500 mL of saturated aqueous solution of sodium carbonate (Na2CO3) and 1 L of water. After drying over sodium sulphate (Na2SO4) and concentration under reduced pressure, we obtain 62 g of (2E)-3-(2,6-dimethoxyphenyl)acrylonitrile in the form of brown oil, which is used “as is” in the next stage.

Workup

  1. additionAdd
  2. temperatureReflux the reaction mixture for 15 h
  3. distillationdistilling the toluene-water azeotrope in Dean-Stark apparatus
  4. temperature40 mL pyridine and reflux again for 48 h in the Dean-Stark apparatus
  5. concentrationAfter concentration under reduced pressure
  6. washwash successively with 1 L of 1N HCl aqueous solution, 500 mL of saturated aqueous solution of sodium carbonate (Na2CO3) and 1 L of water
  7. dry with materialAfter drying over sodium sulphate (Na2SO4) and concentration under reduced pressure, we

Sources & evidence

ORD record
ord-c060882696b24bc28e066d00d9cff23e
Source dataset
uspto-grants-2013_10
Patent number
US08552201B2

Reaction notes

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