piperidine this compound is brominated with ph 3 p br 2 which produces 4 bromo 1 2 4 fluorophenyl ethyl piperidine this compound is contacted with mg thereby forming a grignard reagent which is then reacted with 2 3 dimethoxybenzaldehyde which produces the desired product u00b1 alpha 2 3 dimethoxyphenyl 1 2 4 fluorophenyl ethyl 4 piperidinemethanol the isomer of alphamethoxyphenylacetic acid is known in the art referring to scheme ii x is chloro or bromo with chloro being preferred and r is as previously defined this reaction scheme shows the making of the sustained release compounds of formula i from the alcohol 5 the alcohol 5 is reacted with an acid halide rc o x rco 2 h or acid anhydride rco 2 o in the presence of an a sufficient amount of an appropriate base an appropriate base is one that permits ester formation from the acid halide or anhydride examples of appropriate bases are trialkylamines pyridine such as dimethylamino pyridine diisopropyl ethyl amines n methyl morpholines with triethylamine being preferred a sufficient amount of the base can be ascertained by one skilled in the art which permits the formation of the compounds of formula i preferably the base is added to the alcohol 5 and that mixture added dropwise to the acid halide or acid anhydride in an appropriate solvent examples of appropriate solvents are chloroform methylene chloride or toluene all of which are readily available with chloroform being preferred the temperature of the reaction may be at a range of about 0 25 u00b0 c the reaction mixture may be stirred for from a few hours to overnight to enhance the reaction catalysts may also be added for enhancement of reaction times e g 4 dimethylaminopyridine or the like the starting materials for.