2,4-DIMETHYL-3-CYCLOHEXENECARBOXALDEHYDE synthesis

Yield:68039-49-6 99%

Reaction Conditions:

at 10 - 120; under 1500.15 Torr; for 4.08333 h;

Steps:

2 (2) Addition reaction
By adding a certain percentage of the canned motor pump methyl pentadiene and acrolein to the high pressure synthesis reactor,Open agitation,Slow heating,Each heating 10 ,Open the cooling water to cool for 5 minutes,Until heated to the pot temperature 115-120 ,Stop heating, Maintaining kettle temperature,Control pressure within 0.2Mpa,Insulation reaction 4h.After the reaction,Cooled to 40-45 ,Pressure is atmospheric pressure,Material into the distillation pot,Distillation,With methylpentadiene,Acrolein and ligustral boiling point of different physical properties,The temperature was controlled at 80-85 ° C. Unreacted methylpentadiene,Acrolein is distilled off,The distilled methylpentadiene,Acrolein is condensed back to the autoclave.At a temperature of 80-85 ° C,Distillation can not be distilled,Distillation of the product was cooled to obtain crude ligustral. The crude product of ligustral was vacuum-distilled again,Control the operating pressure is less than -0.08MPa,The temperature is 77-78 ,A fraction of 75-78 ° C / 1.3 KPa was collected,After condensation, 99% of the ligustral product is obtained.Pre-cut (including acrolein, methylpentadiene, etc.)And distillation residue (including acrolein, methylpentadiene, water, etc.) collected as hazardous waste outside the Committee,The project uses three condensing,Including a frozen brine condensate and two water-cooled,Condenser stainless steel coil condenser,Heat transfer area of 20m2,Circulating cooling water a water temperature of 25 ,The water temperature is 35 ,Secondary cooling water cooling water inlet temperature of 25 ,The water temperature is 28 ,Working medium frozen brine inlet temperature of -15 ,Water temperature is -5 .Water (boiling point 100 ),ligustral (boiling point 78 ) condensation efficiency of 99.5%, respectively,Acrolein (bp 52.5 ° C),The condensation efficiencies of methylpentadiene (boiling point 76 ° C) were 98%.

References:

Ningxia Ji Hua Environment Security Technology Co., Ltd.;Hu Jianghai;Zhang Xiaolei;Yu Fei CN106699538, 2017, A Location in patent:Paragraph 0008

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