ε-caprolactone was prepared by coupling of crotonaldehyde oxidation instead of benzaldehyde oxidation and cyclohex-anone oxidation,i.e.,co-oxidation method,under non-catalytic conditions.The effects of solvent type and dosage,reaction temperature,reaction time,oxygen flow rate and feed ratio on the oxidation reaction were mainly investigated.The results showed that the satisfying reaction efficiency could be achieved when ethyl acetate with high polarity was used as the reaction solvent;the conversion rate of cyclohexanone was 41.77%,the selectivity of ε-caprolactone was 94.06%,the conversion rate of crotonalde-hyde was 83.07%,and the selectivity of crotonic acid was 95.49%when the oxygen/crotonaldehyde oxidation of cyclohexanone to ε-caprolactone was carried out under the optimal reaction conditions as follows:15 mL ethyl acetate,12 mmol cyclohexanone,24 mmol crotonaldehyde,reaction temperature of 40℃,reaction time of 12 h and oxygen flow rate of 10 mL/min;and it was feasible to prepare ε-caprolactone by co-oxidation process while yielding the by-product crotonic acid with high added value.
维普
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