596523 Disclosed herein is a process for the preparation of ibodutant which comprises preparing the intermediate (12) through the following steps: a') protection of the primary amine of 4-aminomethyl-piperidine (2) with ethyltrifluoroacetate, followed by reductive amination, preferably with borane Na(AcO)3BH, of protected 4-aminomethyl-piperidine with 4-formyl-tetrahydropyran and a borane and by deprotection in basic medium to yield the intermediate diamine (11) b') reaction of the diamine (11) with Boc-D-Phe to give the intermediate (12) or alternatively through the following steps: a") reaction between 4-aminomethyl-piperidine (2) and Boc-D-Phe(OSu) to yield the intermediate (17) b") reductive amination, preferably with borane Na(AcO)3BH, of (17) with 4-formyltetrahydropyran and a borane to give the intermediate (12), deprotection of the intermediate (12) to yield (4) reaction between (4) and the compound (3), preferably in AcOEt as the solvent, for a time of 10 to 30 hours, thereby obtaining the final product. Optionally further comprising the crystallization of ibodutant in ethanol. Optionally further comprising the following steps for preparing compound (3): activation of 6-methyl-2-benzo[b]thiophenecarboxylic acid of formula (1) to the corresponding acyl chloride； reaction between (1) and l-amine-alpha,alpha-cyclopentane carboxylic acid to yield the intermediate (16) cyclization of (16) to the corresponding oxazolone of formula (3). Further comprising the preparation of 6-methyl-2-benzo[b]thiophenecarboxylic acid (1) by means of catalytic hydrodehalogenation
