Modification of the Teaching Experiment ofPreparation of Cyclohexanone

The preparation of cyclohexanone is one important organic chemistry teaching experiment. In this paper, we modified the experimental operation to prepare cyclohexanone using K₂Cr₂O₇ instead of Na₂Cr₂O₇·2H₂O as oxidizing agent. The solids of K₂Cr₂O₇ were directly added to the round flask with the mixture of cyclohexanol and diluted sulfuric acid in one/two/three portions, the reaction temperature is controlled between 55~60 ℃ through heating or cooling, the reaction time is controlled in the range of 20~30 min, cyclohexanone can be obtained in good yields. The distillate from the simplified steam distillation can be extracted directedly using methyl tertiary-butyl ether (MTBE). The combined organic phase is easier to dry and easily separated from the drying agent. The modified experiment procedure has a good reproducibility and stable yield and can be promoted in other universities.