Studies On Synthesis Of 2-(1-Cycloexenyl) Cyclohexanone From Cyclohexane

2-(1-Cycloexenyl) cyclohexanone is one of most important fine chemicalindustry products, which can be synthesized from cyclohexanone over acid/basecatalysts. 2-(1-Cycloexenyl) cyclohexanone is the intermediate of synthesizingo-phenylphenol(OPP) which shows prospective future in many fields, includingdying, preservatives, textile, auxiliaries, surface activator, flame retardant andthermal stabilizator. Furthermore, 2-(1-cyclohexyl acetate)cyclohexanone, derivedfrom the esterification of 2-(1-Cycloexenyl)cyclohexanone and acetic , is theprecursors of [1,1'-biphenyl]2,2'-diol, which is widely used in the fields of plasticand insecticides etc. OPP shows prospective future in many fields. However, the market demandof OPP is about 5000 t/year and the output is no more than two hundred in ourcountry, which can't meet the demand of the domestic market greatly. The outputof cyclohexanone is abuout 200,000 tons/year, which is far more than thedomestic demand, so enlarging the fields of the products from cyclohexanone isvery necessary. So, as the intermediate to synthesize OPP, the research on thesynthesis of 2-(1-Cycloexenyl) cyclohexanone is very necessary. In this paper, we systematicically studied the catalytic performance ofacid/base catalyst in the condensation of 2-(1-Cycloexenyl) cyclohexanone fromcyclohexanone, and the reaction mechanism of reaction was also presented anddiscussed. Furthermore, the catalytic activity was investigated over nano-MCMzeolites which were characterized by means of XRD , NH3-TPD andacetonitrile-d-3 techniques. The prompt reaction conditions were also abtained.The catalytic performance of spinel compound in the preparation oftrimethylhydroquinone was investigated in this paper. Furthermore, the structureanalysis of various products during raction processes was also presented here.The main work of this paper focuses on the following aspects:1. We systematically studied the catalytic performance of acid/base catalystin the condensation reaction of cyclohexanone, and optimized reactioncondition in addition. On basis of the reaction results, we concluded that HClis the most suitable protonic acid catalyst for the homogeneous reaction. Theoptimal condition for the reaction were: amount of catalyst 5%, reactiontemperature 137 ℃, reaction time 3h, and the conversion of cyclohexanone is54%, the selectivity of dimer is 89%;Fe2(SO4)3 and FeCl3 also showedhighly catalytic activity.2. The present paper made an exploratory study of the catalysticperformance of HMCM-49 zeolite which acidic property and pore structure issimilar to HZSM-5 zeolite. The results exhibited that HMCM-49 zeoliteshowed better catalytic performance than HCl. The conversion ofcyclohexanone will reach 53%, and the selectivity to Dimer can reach 90%.3. The catalytic activity of Fe3O4/SiO2 in the synthesis oftrimethylhydroquinone from the hydroxylation was also studied in this paper.We can make some conclusion on the reaction results:(1) The optimum dosage of hydrogen peroxide : TMP/H2O2(moleration)=3:1(2) With the increasing of solvent, the catalystic activity will decreasegradually. When ethanol was used as solvent, high converstion can beabtained, but the selectivity are lower. So we use acetonitril as solvent, whichcan improve the selectivity of the main products and can be simplely used.(3) The conversion increase with the increasing of temperature, while theselectivity showed the inverse trend. When the mass ratio of solvent under 50℃ (acetonitril/TMP) is 2:1, the reaction time is 2h, TMP/Cata(massratio)=20:1 and TMP/Hydrogen peroxide (molar ratio)=3:1, the catalystshowed the best activity.