| 摘要 |
Phenols are prepared from benzene carboxylic acids by reacting the acid in the molten state with oxygen or a molecular oxygen containing gas mixed with steam in contact with catalytic quantities of a copper compound and a rare earth cation. The rare earth metals used have atomic numbers 57 to 71 and include didymium. When benzoic acid is used the reaction takes place at 200 to 250 DEG C. in presence of copper and rare earth benzoates. Preferably the amount of copper compound catalyst is from 0.001 to 0.2 gram atoms per mole of the aromatic acid and the equivalent ratio of rare earth ions to copper ions is 5:1 to 1:5, the equivalent being defined as a gram atom divided by the charge number. Air may be used to supply oxygen at a rate of 0.005 to 0.5 litres per minute per mole of aromatic acid and the molar ratio of water to oxygen introduced is from 2:1 to 20:1. The reaction preferably takes place at atmospheric pressure at 200 DEG to 245 DEG C. The water and oxygen containing gas may be premixed and/or preheated before introducing into the reaction vessel. |
