Production process and product standard of m-aminobenzoic acid

6.
Production process

1) Catalytic hydrogenation method

Catalyst preparation method: slowly add 2% palladium chloride solution to a pot of water and activated carbon, stirring while adding
.
After the addition is completed, the Pd-C catalyst is obtained by filtering after activation with hydrogen gas

In the dissolving kettle, dissolve 302kg of m-nitrobenzoic acid in 400kg of water and heat to below 70°C
.
Adjust pH with 10% lye to make pH>7

2) Iron powder reduction method

First add 250L of water and 128kg of hydrochloric acid into the reduction reactor, then add 210kg of iron powder and 5kg of sodium chloride
.
The temperature was increased and kept at 95°C for 30 minutes, and 200kg of m-nitrobenzoic acid was added in batches

7.
Laboratory preparation method

In a three-necked reaction flask, add 200mL of water, 102.
5g of hydrochloric acid, 168g of reduced iron powder and 4g of sodium chloride, add 160g of m-nitrobenzoic acid in portions at 95°C, stir and keep at 100°C for 1 hour, and cool to 80°C.
℃, use soda ash to neutralize to above pH-9
.
Press filter at 50°C, and wash the filter mud with water

8.
Product Standard

9.
Product use

Mainly used in the pharmaceutical industry and dye industry, it is an intermediate for the manufacture of azo dyes, iodobenzoic acid and cholangic acid; it is also a reagent for the determination of copper
.

10.
Security measures

(1) The raw material m-nitrobenzoic acid used in production is poisonous, and the product is an organic drug and corrosive
.
The production equipment should be closed, the workshop should be well ventilated, and the operators should wear labor protection equipment

(2) Packed in woven bags lined with plastic bags, protected from heat and sun, and stored in a cool and ventilated place
.
Store and transport in accordance with toxic chemicals regulations