107.7 kg (1 eq.) of intermediate 7-fluoro-4-[2-[4-(thieno[3,2-c]pyridin-4-yl)piperazin-1-yl]-2-oxoethyl]quinolin-2(1H)-one (I), followed by 3231 of THF, are introduced, in thirty minutes at 10° C., into a suspension of 22.2 kg (2.3 eq.) of lithium aluminium hydride in 580 l of tetrahydrofuran, in a reactor. The mixture is stirred for three hours at ambient temperature and then, after verification that the reaction is complete, the mixture is cooled and 21.5 l of water, 21.5 l of 4N sodium hydroxide and 180 l of water are added successively without the temperature exceeding 15° C. The mixture is stirred for one hour and the inorganic salts are filtered off. The mixture is concentrated to three volumes of THF and run into 1400 l of water. The mixture is filtered and a paste is re-formed in 1000 l of a water/THF mixture: 3/7. The product is dried under vacuum at 50° C. Compound (V) is obtained.
