| 摘要 |
Pyridine and alkyl derivatives thereof are prepared by thermal hydrodealkylation of alkyl and/or alkenyl derivatives of pyridine in the presence of molecular hydrogen at a temperature of from 625 DEG to 900 DEG C., at a pressure of from 5 to 60 atmospheres gauge, in a reactor made at least partly of metal, and in the presence of at least one sulphurated compound, particularly carbon disulphide or hydrogen sulphide, the ratio by weight of the sulphur contained in the or each sulphurated compound and the starting material of alkyl and/or alkenyl derivatives of pyridine being from 0.005:100 to 5:100. Examples describe the production of mixtures of pyridine, 2- and 3-picoline, 3-ethylpyridine and 2,5-lutidine from 2-methyl-5-ethylpyridine, of mixtures of pyridine and 2- and 3-picoline from pyridic bases obtained as by-products in the synthesis of 2-methyl-5-ethylpyridine from paraldehyde and ammonia, and of mixtures of pyridine and 2-picoline from pyridic bases obtained from coal tar distillation. |
