Product performance and production technology of m-nitrobenzoic acid

Nitrobenzoic acid (m-nitrobenzoic acid), also known as 3-nitro benzoic acid of the formula C _.
7 H _.
5 NO _.
4 , a molecular weight of 167.
12, the formula

1.
Product performance

White to slightly yellow monoclinic leaf crystals, melting point 140～420℃; relative density (d ₄ ²⁰ ) 1.
494; soluble in acetone , chloroform, ethanol and acetaldehyde, slightly soluble in benzene, water, carbon disulfide and petroleum ether ; with almonds Taste; toxic; acidic, irritating to the skin
.

2.
Production principle

Benzoic acid is nitrated with sodium nitrate in the presence of sulfuric acid to obtain the product
.

3.
Process flow

4.

5.

Nitrification reactor, refined gold, centrifuge, acidification kettle, suction filter, drying oven
.

6.
Production process

In the nitration reactor, add 360kg of concentrated sulfuric acid and heat it to 40°C, then slowly add 104kg of dried and ground sodium nitrate and 100kg of benzoic acid, heat up to 90°C, and heat the nitration reaction for 1.
5h
.

7.
Product Standard

8.

The content is determined as follows:

Take 100 mL of ethanol and add 2 drops of indicator
.

Weigh 0.
5g sample (weigh to 0.
001g), put it in an Erlenmeyer flask with a ground stopper, and put 50mL of neutralized ethanol in two bottles respectively, without adding sample ethanol as the end point colorimetric standard
.

Where: V——Volume of potassium hydroxide standard solution consumed, mL;

c——The concentration of potassium hydroxide standard solution, mol/L;

G——The mass of the sample, g
.

9.

In the pharmaceutical industry, it is used to produce cholinergic acid, acetoiodobenzoic acid, etc.

10.

(1) Sulfuric acid and other corrosive or toxic chemicals are used in production, and this product is toxic.

(2) Sealed packaging, stored in a cool and ventilated place, and stored and transported in accordance with the regulations for organic drugs