Study Of Preparing 1-nonanol From Mixed Octenes

The 1-nonanol is a raw material for surfactants,plasticizers,defoamers and many other fine chemicals synthetization.The performances of the plasticizer prepared with 1-nonanol,such as volatile,oil resistance,water resistance,and insulation et al.,are better than those prepared with traditional methods,which indicated higher commercial prospects.In our work,2-octanol was treated with acid-catalyzed dehydration and mixed octenes(mainly contains of 1-octene and 2-octene)were prepared.Secondly,the mixed octenes were processed with rhodium phosphine complex-catalyzed hydroformylation and n-nonaldehyde had been prepared with high selectivity.Finally,the 1-nonanal was prepared by catalytic hydrogenation of the purified n-nonaldehyde.The 2-octanol was dehydrated with p-toluenesulfonic acid and mixed octenes were obtained.The mixed octenes consist of 1-octene(content of 13.4%),cis-2-octene(content of 14.1%)and trans-2-octene(content of 72.4%),and the combined yield was 82.1%.Two catalyst ligands for hydroformylation of olefins were synthesized,which were triphosphoramidite and bisphosphite ligands.Rhodium dicarbonyl acetylacetonate were combined with triphosphoramidite,bisphosphite and triphenylphosphine,respectively.The combined complex catalysts were used in homemade mixed octenes hydroformylation,the effect of the reaction conditions,such as concentration of rhodium complex,temperature,syngas pressure and the mole ratio of phosphine to rhodium on the activity and selectivity of hydroformylation was investigated.1.The triphosphoramidite was used as catalyst ligand.The molar ratio of ligand and rhodium was 4:1,the molar ratio of the catalyst(based on Rh atom)was 0.02% of the reactants,the reaction pressure is 1 MPa,the temperature was 90 and the reaction time ℃was 15 h.The conversion rate of mixed octenes was 80%,the product selectivity of n-nonaldehyde was 98.8%.2.The bisphosphite was used as catalyst ligand.The conversion ratio of mixed octenes was up to 83% and the ration of n-nonaldehyde was 98.3% at the mole ratio of catalyst(based on Rh atom)to substrate of 0.02%,molar ratio of ligand to rhodium of 5:1,syngas pressure of 1MPa,reaction temperature of 100℃ and reaction time of 14 h.3.The triphenylphosphine was used as catalyst ligand.The concentration of rhodium was 350mg/L and the molar ratio of ligand and rhodium was 200:1,the reaction temperature was 120 ℃,the pressure was 2 MPa and the reaction time was 24 h.The conversion rate of mixed octenes was 69.6%,the product selectivity of n-nonaldehyde was 21.8%.After careful consideration,Raney nickel was used as the catalyst for the reduction of n-nonaldehyde.With the mass ratio of the catalyst was 3.0% of the reactants,hydrogen pressure was 4 MPa and temperature was 120 ℃,the conversion rate of n-nonaldehyde was as high as 99.4% and almost no by-products determined after reaction for 4 h.The final product were characterized by nuclear magnetic resonance spectrum of hydrogen and carbon spectrum.