Chemical Development of an α2δ Ligand, (3<i>S</i>,5<i>R</i>)-3-(Aminomethyl)-5-methyloctanoic Acid
作者:Lorraine Murtagh、Catherine Dunne、Gino Gabellone、Niamh J. Panesar、Stuart Field、Lisa M. Reeder、James Saenz、George P. Smith、Kyle Kissick、Carlos, Martinez、John G. Van Alsten、Margaret C. Evans、Lloyd C. Franklin、Thomas Nanninga、John Wong
DOI:10.1021/op2001832
日期:2011.11.18
Three synthetic approaches, suitable for the large scale manufacture of the alpha 2 delta-ligand, (3S,5R)-3-(aminomethyl)-5-methyloctanoic acid 3, have been evaluated. The selected seven step manufacturing process has then been optimized and used to deliver over 20 kg of API; salient features of the synthesis include the use of 4,4,4-trimethoxybutyronitrile as an efficient four carbon amino acid equivalent. Highly selective kinetic resolution of the C3 stereocente was accomplished via diastereoselective hydrolysis of a cyanoester intermediate using Amano Lipase PS-SD. Extensive process optimisation of the route starting from (R)-2-methylpentanol, led to significant improvements through telescoping, with less than 62 kg of solvent being needed to produce 1 kg of API.