2-chloro-4-nitroaniline (2-chloro-4-nitroaniline) is also known as o-chloro- p -nitroaniline, 4-amino-3-chloronitrobenzene (4-amino-3-chloronitrobenzene), the molecular formula is C 6 H 5 CIN 2 O 2 , the molecular weight is 172.
58, and the structural formula is
1.
Product performance
Yellow needle-like crystals, melting point 107～109℃; soluble in ethanol , ether , carbon disulfide and benzene, slightly soluble in water and 50% acid, insoluble in crude gasoline; toxic
.
2.
Production principle
After p-nitroaniline is salted with hydrochloric acid, it is chlorinated with sodium hypochlorite to obtain the product
.
3.
Process flow
4.
Technical formula (kg/t)
5.
Main equipment
Reaction pot, filter press, storage tank, dryer
.
6.
Production process
Add 450L of water, 1120kg of 30% hydrochloric acid to the reaction pot, increase the temperature to 50°C, add 185.
6kg of p-nitroaniline, and stir for 20min to dissolve
.
Add ice to cool down to about -2°C, slowly add 1120kg of 10% sodium hypochlorite solution from below the liquid surface, use starch potassium iodide test paper to test at any time during the reaction, it should be slightly blue
.
After about 4h, the feeding is finished, keep 0～2℃ and continue to stir and react for 2h.
Check with potassium iodide starch test paper and still show light blue unchanged, which is the end point
.
Add water to adjust the volume to 6000L, let it settle for precipitation, and remove the upper layer of waste acid
.
Add water to a total volume of 6000L
.
After stirring, let it stand, remove the waste acid layer, press filter, rinse with clean water, and dry, and the finished product is about 200kg
.
7.
Product Standard
8.
Quality inspection
Assay: Accurately weigh about 2.
5g sample, place it in a 400mL clean drying cup, add 30mL hydrochloric acid and 100mL distilled water, heat and dissolve on an electric stove, add distilled water to dilute to a total of 300mL
.
This solution is cooled to 0 ~ 10 ℃
.
Then insert the tip of the burette into the solution, and under constant stirring, add 0.
5mol/L sodium nitrite standard solution (95% of the required amount) at once
.
Then take the tip of the burette out of the liquid surface, rinse the tip of the burette with distilled water, add 0.
5mo/L sodium nitrite standard solution drop by drop until the solution makes the potassium iodide-starch test paper slightly blue, and keep it for 5 minutes without fading, that is the end point
.
Do a blank experiment at the same time
.
In the formula: c——molar concentration of sodium nitrite standard solution, mol/L;
V——The volume of sodium nitrite standard solution consumed by the sample, mL;
V 1 ——The volume of sodium nitrite standard solution consumed in the blank experiment, mL;
G——The mass of the sample, g
.
9.
Product use
Used as dyes, pigments and pharmaceutical intermediates, such as the synthesis of Disperse Red B, Silver Bead R, and Schistosomiasis-67 paste
.
10.
Security measures
(1) The raw material is highly toxic to nitroaniline, and the maximum allowable concentration in the air is 0.
0001%
.
The product is an organic drug
.
The chlorination equipment should be sealed, the operators should wear labor protection equipment, and the workshop should be well ventilated
.
(2) The products are packed in iron drums or plastic bags and stored in a cool, dry place
.
Store and transport in accordance with toxic chemicals regulations
.
