| 摘要 |
1357207 Pyridine from α-picoline STAMICARBON NV 26 Nov 1971 [4 Dec 1970] 55094/71 Heading C2C The invention comprises a process for the preparation of pyridine by gas-phase demethylation of α-picoline with steam at 250-360‹ C. in the presence of a metallic hydrogenation catalyst using a contact time of 0À5-15 seconds. Contact times are obtained by dividing the catalyst volume by the volume rate of flow per second of the gas mixture measured at any desired temperature and corrected to the reaction temperature and pressure. It is preferred to employ 4-25 moles of steam per mole of α- picoline in the reaction gas and a preferred catalyst is nickel on alumina or silica gel. Other catalyst metals specified are nickel, cobalt, platinum, palladium and ruthenium. Some 2,6-lutidine is produced during the reaction (#3%)# the amount may be increased by adding hydrogen to the reaction gas, preferably in an amount of 2-20 moles per mole of α-picoline. The gaseous reaction effluent is condensed and may then be extracted, e.g. with benzene and the resulting solution fractionally distilled. |
