P-Cresol → Benzaldehyde, 2-hydroxy-5-methyl-

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Reaction Conditions

Reaction Steps

28.8 g of p-cresol (0.26 mol) are dissolved in 100 ml of water in a round-bottomed flask containing 80 g of NaOH. The mixture is heated to 60-65° C. and 40.5 ml of CHCl3 (0.51 mol) are added in several portions over a period of 30 to 40 min. The mixture is refluxed for 1 h and then cooled. The excess chloroform is removed by distillation under reduced pressure. The medium is acidified with dilute H2SO4 and then subjected to vapor entrainment. The distillate collected (±500 ml) is extracted with ether. The solvent is removed by distillation under reduced pressure. The residue is taken up in 100 ml of saturated sodium bisulfite solution. After vigorous stirring for 2 h, followed by leaving to stand for 1 h, the bisulfite adduct precipitated is collected by filtration and washed with ether. The bisulfite combination is decomposed by heating on a water bath in dilute H2SO4 for 30 min. The aldehyde is extracted with ether. The ether solution is dried over MgSO4. The solvent is removed under reduced pressure. The residue is recrystallized from ethanol.

Provenance & Evidence