Production technology and quality inspection of p-methyl o-nitroaniline

6.
Production process

1) Acylation condensation

First add 1500L of water into the reaction kettle, heat to 85℃, then add 534kg of p-toluidine (100% converted), then slowly add 950.
3kg of p-toluenesulfonyl chloride, while constantly adding soda lye to control the pH of the feed solution Is 8
.

2) Nitrification

First add 180L of chlorobenzene and 450kg of the above acylate into the nitrification kettle, and adjust the temperature to 33～35℃
.

3) Hydrolysis and neutralization

Put 850L of 93% sulfuric acid into the hydrolysis kettle
.

7.
Product Standard

8.

1) Assay

Weigh 1.
5～2.
0g of the sample (accurate to 0.
001g) and place it in a 500mL beaker
.

Where: V—volume of sodium nitrite standard solution consumed during titration, mL;

V ₁ —The volume of sodium nitrite standard solution consumed in the blank experiment, mL;

c——The molar concentration of sodium nitrite standard solution, mol/L;

G——The mass of the sample, g
.

2) Determination of impurities insoluble in hydrochloric acid

Weigh about 5g (accurate to 0.

In the formula: G ₁ ——residue mass, g;

G—The mass of the sample, g

9.

It is mainly used as a developer for dyeing and printing cotton, silk and cotton fabrics, and as an intermediate for the preparation of lakes

10.

(1) P-toluidine and p-toluenesulfonyl chloride are organic drugs, and chlorobenzene is moderately toxic, so care must be taken during operation

(2) It is toxic to methyl o-nitroaniline and cannot be stored and transported with food
.

(3) When transporting, store it in a cool, ventilated and dry warehouse to prevent heat and moisture
.