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Synthetic route of fluorescent brightener 162

Original:www.opticalbrighteners.cnAuthor:Shandong qitai opticEditor:admin Read: Publish time:2019-03-22 10:01【Big Mid Small
(1) process flow:
 
A methylamine
 
|
 
4- chloronaphthalene -1, 8- dimethyl anhydride N- methylation reaction N- methyl -1, 4- chloron1, sodium methoxide
 
8-naphthalimide condensation filtration washing refining product
 
(2) equation:
 
(3) operation: add 30kg water, 30kg40% monomethylamine and 40kg4- into the reactor
 
Chlorine naphthalene - 1, 8 - dimethyl anhydride, heating, reflux, N - methylation reaction, reaction after 1 h, down to room temperature, filtering, get yellow pulp material a chlorine N - methyl - 4-1, 8 - naphthalene imide crude products, recrystallization by injection of acetic acid crude products, get about 30 kg masterwork yellow crystal, its melting point is 166 ~ 168 ℃.
 
Add the above refined products into the reactor, add 60kg30% sodium methyl-methanol solution, add a small amount of sodium acetate, stir and heat reflux for 4-5h. Filter it when it is hot, if it is too thick, a certain amount of methanol can be added to dilute it and then filter it. Then the filtrate will be cooled. The product was washed, dried and recrystallized with methanol or ethanol.
 

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