Hydrogenation process of oxime derivatives

A process for the hydrogenation of an oxime of formula (I) to produce a hydroxylamine salt of formula (II) by reacting oxime (I) with hydrogen in the presence of an iridium catalyst of formula (IIIa) or formula (IIIb) and an acid;

• wherein R1, R2 and R3 are each independently hydrogen, C1-C8alkyl, C1-C8hydroxyalkyl, C1-C8cyanoalkyl, C1-C6alkoxyC1-C8alkyl, di(C1-C6alkoxy)C1-C8alkyl, C1-C8haloalkyl, C2-C6alkenyl, C3-C8cycloalkyl, phenyl, phenylC1-C3alkyl or heteroaryl, and wherein the cycloalkyl and phenyl moieties are each optionally substituted with 1 to 5 groups selected from hydroxyl, halogen, C1-C6alkyl, C3-C8cycloalkyl, C1-C6haloalkyl, C1-C6alkoxy, phenyl, heteroaryl, C1-C6alkoxycarbonyl, acylamino, amido, cyano, nitro and C2-C6alkenyl;
• or
• R1 and R2 together with the carbon atom to which they are attached may form a 4- to 8-membered saturated cycloalkyl or heterocyclyl ring, wherein the heterocyclic moiety is a non-aromatic monocyclic ring which comprises 1, 2 or 3 heteroatoms, wherein the heteroatoms are individually selected from N, O and S;
• R6, R7, R8, R9 and R10 are each independently hydrogen or C1-C3alkyl;
• represents a bidentate chelating ligand comprising at least one carbon atom which coordinates to iridium and at least one nitrogen atom which coordinates to iridium;
• X represents an anionic group of the formula R14—SO2O— or R15—C(O)O—, wherein
• R14 is hydroxy, C1-6alkyl, C1-6alkoxy, C1-6haloalkyl, or phenyl, wherein the phenyl moieties are optionally substituted by 1, 2, 3 or 4 substituents, which may be the same or different, selected from R16;
• R16 is C1-4alkyl, C1-4haloalkyl, nitro, or halogen;
• R15 is C1-6haloalkyl or phenyl, wherein the phenyl moieties are optionally substituted by 1, 2, 3 or 4 substituents, which may be the same or different, selected from R17;
• R17 is C1-4alkyl, C1-4haloalkyl, nitro or halogen;
• Y represents a neutral ligand;
• and
• Z represents an anionic group.