Patent ID: 7462742

Claim:
In situ or one-pot process for the preparation of a compound of general formula (I): in which R 1 is a hydrogen atom, a linear or branched C 1-6 -alkyl, a fonnyl, a C 2-7 -alkanoyl, a benzyl (—CH 2 C 6 H 5 ), a tetrahydrofitranyl, an alkylsilyl or arylsilyl, or a protective group for an oxygen atom, Gp; R2 and R3 independently are a hydrogen atom, a linear or branched C 1-6 -alkyl, a C 1-6 -alkoxy (—OAk), a C 1-7 -alkanoyloxy (—OC(O)Ak), a C 1-6 -thioalkyl (—SAk), a halogen atom (Cl, Br, F), a trifluoromethyl (—CF 3 ), an “oxy” group where the oxygen atom is bonded to a protective group for the oxygen atom, or a substituted or unsubstituted C 6-10 -aryloxy (—OAr), or R2 and R3 together form a methylenedioxy (—OR2R3O—); R4 is a hydrogen atom or a linear or branched C 1-6 -alkyl; and n is the integer 0, 1, 2, 3 or4, the process comprising: a) hydrogenation of a nitrile group of the compound of general formula (II): in which R 1 , R2, R3, R4 and n are as defined above, in the presence of a hydrogenation catalyst, a methylating agent and an organic acid as solvent, and at a temperature Ta ranging between 5° C. and 25° C., to give a primary amine from the nitrile group; and b) reductive amination of the primary amine in the presence of hydrogen, at a temperature Tb of between 30° C. and 80° C., by, at the end of hydrogenation of step a), raising the temperature of the reaction medium to said temperature Tb to give the dimethylated amine of general formula (I) by activation of the methylating agent.