Process for the production of the dinitriles of fumaric acid and maleic acid

A process for the production of fumaric and/or maleic dinitrile comprises treating succinonitrile with a gas containing oxygen or air, at elevated temperature, in the presence of at least one oxide, stable at reaction temperature, of a metal of Group V and/or Group VI of the Periodic Table, which may be supported. Specified oxides are vanadium pentoxide, molybdenum trioxide and chromic oxide; an alkali metal hydroxide may also be present. The reacting gases may contain water, and waste reaction gas may be recycled.ALSO:A catalyst suitable for the production of fumaric and/or maleic dinitrile (see Division C2) comprises at least one oxide of a metal of Group V or VI of the Periodic Table (e.g. vanadium pentoxide, molybdenum trioxide or chromic oxide), which may be supported, e.g. on moulded silica gel. Alkali metal hydroxides may also be present. The catalyst may be regenerated after use by treatment with air at 400-650 DEG C. In examples, silica gel bars are impregnated with aqueous solutions of (1) CrO3+KOH; (2) CrO3+(NH4)2MoO4+KOH; and (3) CrO3+NH4VO3+KOH, followed by drying at 120 DEG C. and heating at 450 DEG C.