Patent ID: 7238807

Claim:
A Process for preparing compounds of the formula I wherein R 1 denotes a group selected from the group consisting of chlorine, fluorine, bromine, methanesulphonyl, ethanesulphonyl, trifluoromethanesulphonyl, para-toluenesulphonyl, CH 3 S(═O)— and phenylS(═O)—, R 2 denotes hydrogen or C 1 –C 3 -alkyl, R 3 denotes hydrogen or a group selected from the group consisting of optionally substituted C 1 –C 12 -alkyl, C 2 –C 12 -alkenyl, C 2 –C 12 -alkynyl and C 6 –C 14 -aryl, or a group selected from the group consisting of optionally substituted and/or bridged C 3 –C 12 -cycloalkyl, C 3 –C 12 -cycloalkenyl, C 7 –C 12 -polycycloalkyl, C 7 –C 12 -polycycloalkenyl, C 5 –C 12 -spirocycloalkyl and saturated or unsaturated C 3 –C 12 -heterocycloalkyl, which contains 1 to 2 heteroatoms, R 4 , R 5 which may be identical or different denote hydrogen or optionally substituted C 1 –C 6 -alkyl, or R 4 and R 5 together denote a 2- to 5-membered alkyl bridge, which may contain 1 to 2 heteroatoms, or R 4 and R 3 or R 5 and R 3 together denote a saturated or unsaturated C 3 –C 4 -alkyl bridge, which may optionally contain 1 heteroatom, and “A 1 and A 2 denote —N═”, comprising a) hydrogenating with hydrogen in the presence of a hydrogenation catalyst and a compound of formula II wherein R 1 to R 5 , A 1 and A 2 have the meanings given above and R 6 denotes C 1 –C 4 -alkyl, and b) adding a copper, iron or vanadium compound, wherein in which steps a) and b) may take place simultaneously or successively step b) followed by step a).