Process for the production of substituted 2-[2-(phenyl) ethylamino]alkaneamide derivatives

A process for preparing a compound of formula (I) or a pharmaceutically acceptable salt thereof:

• wherein R is (C3-C10)alkyl, or ω-trifluoro(C3-C10)alkyl;
• R1 and R2 are, independently, hydrogen, hydroxy, (C1-C8)alkoxy, (C1-C8) alkylthio, halo, trifluoromethyl or 2,2,2-trifluoroethyl;
• or one of R1 and R2 is at the ortho position to the R—O— group and, taken together with the same R—O—, represents a
• group where R0 is (C2-C9)alkyl;
• R3 and R4 are independently hydrogen or (C1-C6)alkyl;
• or taken together with the adjacent nitrogen atom form a 5-6 membered monocyclic saturated heterocycle, optionally containing one additional heteroatom chosen among —O—, —S— and —NR7— where R7 is hydrogen or (C1-C6) alkyl;
• R5 is hydrogen or (C1-C6)alkyl;
• and wherein optionally one or more hydrogen atom in the groups R, R1, R2, R3, R4 and R5 can be substituted by a deuterium atom;
• said process comprising the steps of:
• i) reacting a compound of formula (II) or a salt thereof
• wherein R, R1, R2, are as above defined, with a compound of formula (III):
• wherein R3, R4 and R5 are as above defined, under reducing conditions, to obtain the compound of formula (I) as above defined, and
• ii) optionally salifying the obtained compound of formula (I).