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The molecular formula of 4-chloronaphthalene-1, 8-dicarboxylic anhydride (4-chloronaphthalene-1, 8-dicarboxylic anhydride) is C 12 H 5 O 3 Cl, the molecular weight is 232.
63, and the structural formula is
1.
Product performance
Light yellow crystal; melting point 222℃, insoluble in water, slightly soluble in chlorobenzene and glycol methyl ether; toxic; irritating to skin
.
2.
Production principle
In the sodium hydroxide solution, 1,8-forbidden dicarboxylic anhydride reacts with chlorine to produce chlorination to obtain 4-chlorohetero-1,8-dicarboxylic anhydride
.
3.
Process flow
4.
Technical formula (kg/t)
5.
Main equipment
Chlorination reactor, filter, storage tank, dryer
.
6.
Production process
In the chlorination reactor, add 2000L of water and 158kg of 1,8-naphthalenedicarboxylic acid anhydride
.
Add 240kg 30% liquid caustic soda while stirring
7.
Product Standard
8.
Quality inspection
1) Melting point determination
Place the dried sample in an agate mortar and grind finely, and then put it into a clean and dry capillary with one end closed
.
Throw more than ten times through the upright throwing tube until the sample in the capillary tube is compressed to a height of 2 to 3 mm, and the upper end is melt-sealed immediately
2) Assay
Accurately weigh 2.
0g sample, place it in a 300mL conical flask, add 80mL boiled distilled water, heat to melt, then quickly cool, add 2 drops of 1% phenolphthalein indicator, and titrate with 0.
5mol/L sodium hydroxide standard solution to The reddish color is the end point
.
Content (%)=cV×0.
1163/G×100%
In the formula: c——molar concentration of sodium hydroxide standard solution, moL;
V——The volume of sodium hydroxide standard solution consumed by the sample, mL;
G——The mass of the sample, g
.
9.
Product use
Used as a dye intermediate, can be used to produce fluorescent yellow, fluorescent orange and other dyes
.
10.
Security measures
(1) The raw material 1,8-naphthalenedicarboxylic acid anhydride is toxic and can irritate the eyes, mucous membranes and respiratory tract
.
Chlorine is a highly toxic inorganic gas, chlorination equipment should be sealed, operators should wear labor protection equipment, and ventilation in the workshop should be strengthened
(2) This product is toxic, and is sealed in iron drums, stored in a cool and dry place, and stored and transported in accordance with the regulations for toxic chemicals
Related links: Production process and product use of 2-chloro-4-nitrobenzoic acid
