2-hydroxy-3-naphthoyl-m-nitroanilide (2-hydroxy-3-naphthoyl-m-nitroanilide), also known as naphthol AS-BS (naphthol AS-BS), N-(3-hydroxy-2-naphthalene Formyl) meta-nitroaniline, Naftor AS-BS; molecular formula is C 17 H 12 N 2 O 4 , molecular weight is 308.
29, structural formula is
1.
Product performance
Light yellow powder; melting point 246～247℃; soluble in acetic acid , insoluble in water and sodium carbonate ; yellow in sodium hydroxide solution; toxic
.
2.
Production principle
Using chlorobenzene as solvent, meta-nitroaniline is condensed with 2,3-acid in the presence of phosphorus trichloride
.
Then neutralize with sodium carbonate, distill chlorobenzene, then filter and dry to obtain
3.
Process flow
4.
Technical formula (kg/t)
5.
Main equipment
Dehydration kettle, shrink alloy, storage tank, hydrogen chloride absorption tower, neutralization pot, distillation kettle, suction filter, dryer
.
6.
Production process
Add 1400L solvent chlorobenzene and 416kg m-nitroaniline to the dehydration kettle, heat dehydration, and the temperature gradually rises to 134～135℃
.
When the steamed chlorobenzene is clear and anhydrous, stop heating
Add 522kg of 2,3-acid into the condensation kettle, and then press in the above-mentioned dehydrated m-nitroaniline and chlorobenzene solution
.
The temperature of the material is cooled to about 85°C, and the mixed solution of phosphorus trichloride and chlorobenzene (168kg of phosphorus trichloride, 55% to 60% mixed solution of about 112kg of anhydrous chlorobenzene) is added uniformly within 2h
Add 2200L of water and 130kg of soda ash to the neutralization pot, and press the above condensate into it with stirring
.
Stir for 15 minutes, take a sample to determine the pH of the material, and it should be above 8
