| 摘要 |
Preparation of nicotinamide (I) comprises: (a) converting 2-methyl-1,5-diamino-pentane to 3-methylpyridine (III) which is then converted to 3-picoline (IV); (b) treating (IV) in presence of ammonia and oxygen-containing gas at 280-400 degrees C over an ammonia oxidation catalyst (A) to form 3-cyanopyridine (V) and (c) converting (V) to (I) using a microorganism of the genus Rhodococcus. (II) is converted to (III) in the gas phase at 300-400 degrees C and 0-10 bar excess pressure by passage over a catalyst containing as active component≥1 oxide of aluminium and/or silicon, having a surface ratio of acid:basic centres > 2 and specific surface > 40 m<2>/g. Conversion to (IV) is done immediately at 220-400 degrees C over a dehydrogenation catalyst. (A) comprises oxides of vanadium, titanium, zirconium and molybdenum in mole ratio V2O5:TiO2:ZrO2 of 1:1:2-1:12:35 and of MoO3 content, based on V2O5, of 0.54-2.6wt.%. The steps (b) and (c) are claimed together as a distinct process. |
