Patent GB-671763-A (GB)
Title: Cyanopyridine, pyridine carboxamide and cyanopyridine carboxamide compounds and process of producing the same
IPC: C07D213/84
Filed: 1950-04-19
Abstract: Cyano-pyridines, pyridine carboxamides, and cyanopyridine carboxamides are prepared from alkyl pyridines by contacting them in vapour form with ammonia and a free oxygen containing gas in the presence of a catalyst composed of an oxide or salt of a metal of the fifth, sixth or eighth group of the periodic system at elevated temperature.  Starting materials mentioned include the picolines, lutidines and collidines.  The preferred compounds being alkyl pyridines with not more than four carbon atoms in any one alkyl substituent.  Mixed catalysts may be employed.  As the oxygen containing gas air or mixtures of oxygen with carbon dioxide or steam.  The preferred temperatures are from 250-450 DEG  C.  In examples 1-6, 3-picoline is converted into 3-cyanopyridine using as catalyst (1) ferric vanadate; (2) activated alumina soaked in ferric nitrate and ignited, pumice chips soaked in nickel nitrate and ignited; (3) chromic oxide on an aluminium carrier; (4) activated alumina soaked in ammonium dichromate and ignited; (5) vanadium pentoxide on alumina; (6) molybdenum oxide on alumina.  (7) 3-Ethyl pyridine was reacted in the presence of vanadium pentoxide on alumina to give 3-cyanopyridine.  (8) 6 - Methyl - 3 - ethylpyridine is reacted in the presence of ferric vanadate to form 3-cyanopyridine. (9) 6-Methyl-3-ethyl pyridine gives with a vanadium pentoxide catalyst on alumina 3-cyanopyridine.  (10) 4-picoline with the catalyst of example (9) gives 4-cyanopyridine.  (11) 2-picoline with the same catalyst gives 2-pyridine-carboxamide.  (12) 2 : 6-Lutidine with the same catalyst gives 2-cyanopyridine-6-carboxamide which on alkali hydrolysis forms dipicolinic acid.  (13) 6-Methyl-3-ethylpyridine gives with ferric vanadate catalyst 6 - cyanopyridine - 3 - carboxamide.  (14) 6-Methyl-3-ethyl pyridine gives with silver vanadate catalyst 6-cyanopyridine-3-carboxamide. (15) 6-methyl-3-ethyl pyridine gives with a ferric columbate catalyst 6-cyanopyridine-3-carboxamide.  (16) 6-Methyl-3-ethyl pyridine gives with a vanadium pentoxide on alumina catalyst 6-cyanopyridine-3-carboxamide.ALSO:Catalysts for use in the oxidation of alkyl pyridines in the presence of ammonia and a free oxygen containing gas to form cyano-pyridines, pyridine carboxamides ans cyanopyridine carboxamides comprise oxides and salts of a metal of the fifth, sixth or eighth group of the periodic system, singly or mixed and either as two or more different oxides, or as two or more different salts, or as one or more oxides with one or more salts. They may be used on carriers.  The catalysts may be prepared by precipitation from their soluble melts and dried, or calcined to produce the oxide.  The catalyst may also be prepared by spraying the catalytic material on small particles of pumice, clay or silica.  In examples (1) Ferric vanadate catalyst is made by adding ferric chloride to ammonium vanadate, filtering and drying.  (2) Ferric nitrate is soaked into activated alumina, dried and ignited.  (3) Pumice chips are soaked in nickel nitrate and ignited.  (4) Commercial activated alumina is soaked in ammonium dichromate and ignited.  (5) Silver nitrate is added to ammonium metavanadate in molecular amounts and the precipitate filtered and dried.  (6) One mol. of ferric chloride is added to three mols. of potassium columbate, and the precipitate washed and dried.