in which 2 chloropyridine and benzyl cyanide initially are coupled to form u03b1 pyrid 2 yl phenylacetonitrile the resulting u03b1 pyridyl 2 ylphenylacetonitrile then is hydrated in the presence of acid to yield u03b1 pyrid 2 ylphenylacetamide which in turn is catalytically hydrogenated to yield u03b1 piperid 2 ylphenylacetamide and then is hydrolysed and epimerized to dl threo ritalinic acid the solvent used in the step i along with water may be selected from organic solvents the solvent used to dissolve ester of tartaric acid may be selected from organic solvents conventional esters of tartaric acid used may include dibenzoyltartaric acid and ditoluoyltartaric acid the preferred one being dibenzoyltartaric acid of 0 2 to 1 6 eq to that of ritalinic acid preferably 1 06 eq in a solvent preferably methanol adding at a temperature ranging preferably below 50 u00b0 c for a period preferably ranging from 5 min to 5 h heating the mass in step ii at reflux temperature preferably in 1 h to 2 h and filtering the mass through hyflo bed the filtrate is cooled to a temperature preferably 20 u00b0 c to 25 u00b0 c the resulting mass of step iii is maintained under stirring preferably for 13 h before filtering the d threo ritalinic acid tartaric.