SU466215A1 - The method of separation of a mixture of hydrazoanisole and zinc hydroxide - Google Patents

Description

one

This invention relates to a process for the preparation of intermediates, namely the preparation of hydrazoanisole.

A known method for separating a mixture of hydrazoanisole and zinc hydroxide, obtained by alkaline reduction of o-nitroanisole in an aqueous medium, to which zinc hydroxide is converted to zinc sulfate, followed by separation of the hydrazoanisole in a separator.

The residues of this method are the contamination of wastewater with hazardous products - hydrazoanisole and zinc sulfate, the impossibility of utilizing zinc oxide and the complexity of the process technology.

In order to eliminate these drawbacks, a mixture of hydrazoanisole and zinc hydroxide is proposed to be pre-cooled to 36-65 ° C and diluted with 6-12 times the volume of water previously heated to 20-30 ° C.

The proposed conditions make it possible to obtain homogeneous particles of hydrazoanisole, which are much larger in size than zinc oxide particles, which makes it possible to carry out separation in a known manner, for example, in a separator, without significant loss of the desired product.

Example 1. Separation of hydrazoanisole and zinc hydroxide contained in the reaction mass obtained by chilling alkali reduction of o-nitroanisole in factory gearboxes.

1800 kg (1200 l) of the reaction composition (in kg): hydrazoanisole 370.8; hydroxide

zinc 927.7; water 501.5, obtained in the reducer after the reduction process, is cooled to 52 ° C, diluted with an equal volume of water, preheated to 25 ° C, then the mass is transported using

vacuum into the apparatus with a stirrer and dilute another 6000 l of water with a temperature of 25 ° C. After stirring for 10 minutes, the mass is fed into the pressure tank, from where it flows by gravity to separate it into the separator operating in production. Hydrazoanisole on the separator grid is washed with 9000 liters of water with temperature.

After separation, 987.7 kg (800 L) of hydrazoanisole paste of composition (in kg) are obtained:

hydrazoanisole 350; water 570; zinc hydroxide 67.7 N 17012.3 kg (16600 l) of zinc hydroxide suspension containing (in kg): zinc hydroxide 860; hydrazoanisole 20.8; water 16,131.5.

Example 2. 1800 kg (1200 l) of the reaction mass of the composition (in kg): hydrazoanisole 371.0; zinc hydroxide 930; water 499, obtained in the reducer after the reduction process, is cooled to 35 ° C and diluted with

preheated water

to 30 ° C, then the mass is transported to the apparatus with a mixer and diluted with another 11-fold volume of water with a temperature of 30 ° C. Next, the process is carried out as in example 1. Hydrazoanisole on the separator grid is washed with 9000 l of water with a temperature of 30 ° C.

After separation, 1016.5 kg (850 L) of hydrazoanisole paste of composition (in kg) are obtained: hydrazoanisole 349.5; water 600; zinc hydroxide 67.0 and 24183.5 kg (23750 l) of zinc hydroxide suspension containing (in kg): cinnamon hydroxide 863; hydrazoanisole 21.5; water 23299.

Example 3. 1800 kg (1200 l) of the reaction composition (in kg): hydrazoanisole 368.5; zinc hydroxide 925.5; water 506.0 obtained in the reducer after the reduction process is cooled to 65 ° C and diluted with an equal volume of water with a temperature of 20 ° C, then the mass is transported to an apparatus with a blender and diluted with another 8-fold volume of water with a temperature of 20 ° C . Next, the process is carried out according to example I. Hydrazoanisole on the separator grid — washed with 9000 l of water with a temperature of 20 ° C.

After separation, 994.7 kg (800 L) of hydrazoanisole paste of composition (in kg) are obtained: hydrazoanpozol 350.2; water 580.0; zinc hydroxide 64.5 and 20605.3 kg (20200 l) of zinc hydroxide suspension containing (in kg): zinc hydroxide 861; hydrazoanisole 18.3; water 19726.

Subject invention

A method for separating a mixture of hydrazoanisole and zinc hydroxide obtained by alkaline reduction of o-nitroanisole in an aqueous medium in a known manner, characterized in that, in order to simplify the process, this mixture is pre-cooled to 35-65 ° C and diluted 6-12- multiple water volume of poi 20-30 ° C.