Benzaldehyde → 4-METHOXYBENZOIN

HRID 1460898Notes

Reaction equation

HRID 1460898 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 flash-chromatography (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 flash-chromatography (on silica Merck-60, preabsorbed in dichloromethane-ethyl acetate and eluted with hexane-ethyl acetate 8:2)

Sources & evidence

ORD record
ord-faa4f388ae5c4230b4ed2aecc73108a4
Source dataset
uspto-grants-1991_12
Patent number
US05071988

Reaction notes

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