| 摘要 |
<p>Mono-and di-lower alkyl substituted pyridines can be converted to pyridine nitriles by reaction with ammonia, in the substantial absence of free oxygen, and in the presence of a transition metal oxide catalyst. Intermediate products can be recycled to the nitrile production step. The nitrile can be converted to the carboxylic acid by; aqueous hydrolysis, in the presence of ammonia or ammonium salts, at temperatures between about 200 DEG F and 450 DEG F. Ammonia is stripped from the hydrolysis mixture by passing a stripping gas through the mixture. In a preferred embodiment, the hydrolysis and stripping are performed simultaneously and continuously, with the hydrolysis mixture and stripping gas moving countercurrently to each other.</p> |
