摘要 |
<p>A process is disclosed for the preparation of a piperazine-substituted aliphatic carboxylate having formula (I) where m and n are individually an integer of from 1 to 6, R and R' are the same or different and are hydrogen, C1 to C6 alkyl or aryl or heteroaryl that is unsubstituted or is substituted with at least one substituent that is halo, C1 to C6 alkyl or C1 to C6 alkoxy and R'' is C3 to C12 branched alkyl or an organic or inorganic cation. The process comprises treating a solution comprising a compound of formula (II) wherein m, R and R' are as defined above and an aliphatic ester of the formula (III): X-(CH2)nCO(O)R'', where X is a leaving group and n and R'' are as defined above, with a base in the presence of an effective amount of a phase transfer catalyst, for a time and at a temperature sufficient to form a piperazine-substituted aliphatic carboxylate. Hydrolysis of the carboxylate with acid produces a piperazine-substituted aliphatic carboxylic acid or the acid salt thereof.</p> |