Green Synthesis Of L-2-Amino-Propanol

L-2-amino propanol is important intermediate for levofloxacin of quinolone antibacterial drug.In this thesis,three synthetic processes for L-2-amino propanol were studied and compared including pre-esterification and post-chemical reduction,chemical reduction and catalytic hydrogenation,using L-alanine as raw material.These processes were improved and optimized,and the optimized parameters were gained.The process of catalytic hydrogenation is the best process because of its lower production cost and less waste ignoring its lower optical purity and safety.The process of catalytic hydrogenation was as follows:Ru nanoparticle was prepared by reducing Ru2(dba)3 using hydrogen in 1,2-propanediolcyclic carbonate/water solution.Ru/C nanocatalyst was gained using activated carbon as adsorbing agent.L-alanine was reduced by hydrogen using Ru/C as catalyst and water as solvent,and L-2-amino propanol was gained after extraction,drying,desolution and rectification.The optimized conditions for preparing 5%Ru/C nanocatalyst were as follows:Ru2(dba)3was reduced by hydrogen at 30? under 2MPa for 2h in 5%1,2-propanediolcyclic carbonate/water solution.Using activated carbon as adsorbing agent,5%Ru/C nanocatalyst was gained after filtration and vacuum drying.The optimized conditions for preparing L-2-amino propanol were as follows:water was used as solvent,the concentration of L-alanine was 0.67mol/l,the dosage of 5%Ru/C nanocatalyst was 10%to the mass of L-alanine.L-alanine was reduced at 100? under 8MPa for 9h.L-2-amino propanol was gained after extraction,drying,desolution and rectification.The yield was 86%,the purity was 99.8%and the optical purity was 99.73%.L-2-amino propanol was prepared by catalytic hydrogenation from L-alanine.It had high yield,low production cost and less waste.The equivalent reaction of chemical reduction was replaced by catalytic reaction.It was clean reaction with good use ratio of atom.It is expected to create good economic and social benefits.