Synthesis Of Iodo-substitued Aromatic Compounds And β-enamine Ketones(esters)in A Micro-channel Reactor

Microreactor is a special reactor for continuous flow of pipeline.The pipe size is in the micrometer to millimeter size range,which is far less than conventional tubular reactors.The small pipe size means there are a lot of specific surface in microstructured reactor,which bring the fundamental advantages are great mass transfer efficiency,great heat transfer efficiency,great safety performance,precise control of the reaction temperature,reaction time and reactant molar ratios.The reactions for synthesis of iodo-substitued aromatic compounds andβ-enamino ketones（esters）in microreactor were studied in the dissertation.The process for synthesis of iodo-substitued aromatic compounds via the reaction between iodination of diazonium salt and potassium iodide was investigated in a microreactor.A model study was initiated with iodobenzene as substrate.The effects of tube diameter,flow rate,reaction time and reaction temperature on yield were performed.The optimum conditions were determined as follows:tube diameter 0.8mm,flow rate 1004.8μL/min,reaction temperature 20 ℃,reaction time 75s.The yield of iodobenzene was 79.0%under these conditions.The STC in micro-channel reactor was 9.41×10³ mol·m^-3·h^-1,more than 100 times of that in a regular reactor.In the optimum process parameters,a series of 9 iodo-substitued aromatic compounds were synthesized.The yield of the products were between 79.0%and 89.6%.All the products were characterized by H-NMR.The process for synthesis of β-enamino ketones（esters）via the reaction between substituted anilines and 1,3-dicarbonyl compounds was investigated in a microreactor.A model study was initiated with 4-（phenylamino）pent-3-en-2-one as substrate.The effects of tube diameter,catalyst content,reactant molar ratios,flow rate,reaction time and reaction temperature on yield were performed.The optimum conditions were determined as follows:tube diameter 0.5mm,catalyst content 15mol%,reactant molar ratios 1:1.4,flow rate 3 92.5μL/min,reaction temperature 78℃,reaction time 120s.The yield of 4-（phenylamino）pent-3-en-2-one was 93.8%under these conditions.The STC in micro-channel reactor was 1.56×104 mol·m^-3·h^-1,more than 40 times of that in a regular reactor.In the optimum process parameters,a series of 12 β-enamino ketones（esters）were synthesized.The yield of the products were between 77.0%and 96.3%.All the products were characterized by 1H-NMR.Compared with traditional methods,this improved synthetic methodology was simple,due to which,the reaction time had been shortened,the yield and STC have been improved.Meanwhile the process could be applied in industry.