Benzaldehyde → 4-METHOXYBENZOIN

HRID 2380158Notes

Reaction equation

HRID 2380158 reaction equation
[C-]#N.[K+].[CH3:4][O:5][C:6]1[CH:13]=[CH:12][C:9]([CH:10]=[O:11])=[CH:8][CH:7]=1.[CH:14](=[O:21])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1.C(O)C>O>[CH3:4][O:5][C:6]1[CH:13]=[CH:12][C:9]([C:10]([CH:14]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[OH:21])=[O:11])=[CH:8][CH:7]=1

Participants

6

Reactant 4

HCID 240BenzaldehydeHCID 702EthanolHCID 9032Potassium CyanideHCID 312444-Methoxybenzaldehyde

Product 1

HCID 37914-METHOXYBENZOINYield 41.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a solution of KCN (5 g) in water (35 mL) is added 4-methoxybenzaldehyde (27.2 g, 0.2 mole), benzaldehyde (21.2 g, 0.2 mole) and 95% ethanol (70 mL). The mixture is refluxed under nitrogen for 4.5 hours and the ethanol removed in vacuo. Water (200 mL) is added to the residue and then distilled off at reduced pressure (to remove remaining unreacted bezaldehyde). The procedure is repeated twice and the residual water azeotroped with ethanol. The crude product (56.3 g, orange semi-solid) is purified by flashchromatography (on silica Merck-60, preabsorbed in dichloromethane-ethyl acetate and eluted with hexane-ethyl acetate 8:2) to yield a light yellow solid (20.1 g, 41.5%), m.p. 99°-101° C.

Workup

  1. temperatureThe mixture is refluxed under nitrogen for 4.5 hours
  2. customthe ethanol removed in vacuo
  3. additionWater (200 mL) is added to the residue
  4. distillationdistilled off at reduced pressure (to remove remaining unreacted bezaldehyde)
  5. customthe residual water azeotroped with ethanol
  6. customThe crude product (56.3 g, orange semi-solid) is purified by flashchromatography (on silica Merck-60, preabsorbed in dichloromethane-ethyl acetate and eluted with hexane-ethyl acetate 8:2)

Sources & evidence

ORD record
ord-7a0aa146d94e4c0cbebe70936b899858
Source dataset
uspto-grants-1994_11
Patent number
US05364944

Reaction notes

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