The invention relates to the field of
fine chemical engineering, in particular to a method for preparing 2-ethylhexyl 4-(dimethylamino)benzoate through hydrogenation by taking water as a
solvent. Themethod for preparing 2-ethylhexyl 4-(dimethylamino)benzoate through hydrogenation by taking water as a
solvent is characterized by comprising the following steps: (1) adding water, 4-nitro-
benzoic acid 2-ethyl-hexyl ester and an active
nickel catalyst into a reactor in proportion; (2) performing heating, introducing
hydrogen, and carrying out heat preservation and pressure maintaining reaction until no
hydrogen is absorbed; (3) cooling, namely adding
paraformaldehyde into the reactor, and supplementing the active
nickel catalyst in proportion; (4) heating, introducing
hydrogen, and carrying out heat preservation and pressure maintaining reaction until hydrogen is not absorbed; (5) continuing to preserve heat and pressure for several hours, terminating the reaction, and sampling and analyzing; (6) after the catalyst is filtered, recycling, activating and reusing the catalyst, standing for layering, discharging a
water layer into a
sewage system, and feeding an oil layer into a
distillation tower; and (7) heating, rectifying and purifying by the
distillation tower until the product specification is met, and barreling and packaging.