2-hydroxy-3-naphthoic acid process and technical formula

2-hydroxy-3-naphthoic acid (2-hydroxy-3-naphthoic acid) is also known as 3-hydroxy-2-naphthoic acid, 2,3-acid, 2-naphthol-3-carboxylic acid (2-naphthol-3 -carboxylic acid), the molecular formula is C ₁₁ H ₈ O ₃ , the molecular weight is 188.
18, and the structural formula is

1.

Yellow oblique flaky crystal; melting point 222～223℃; hardly soluble in cold water, slightly soluble in hot water, soluble in ethanol , ether , chlorobenzene , chloroform and alkaline solution; react with soda ash to generate monosodium salt and double Sodium salt; moderately toxic
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2.
Production principle

After β-naphthol and sodium hydroxide form a salt, heating and decompression are dehydrated, and the obtained anhydrous β-naphthol salt is carboxylated with carbon dioxide to form 2,3-acid disodium salt, which is then acidified with sulfuric acid to obtain a finished product
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4.
Technical formula (kg/t)

5.

Salt formation reactor, carboxylation reactor, separation tank, storage tank, filter press, acidification pot, filter dryer