ChemicalBook CAS DataBase List 1,5-Naphthalenedisulfonic acid

1,5-Naphthalenedisulfonic acid synthesis

12synthesis methods

Product Name:1,5-Naphthalenedisulfonic acid
CAS Number:81-04-9
Molecular formula:C10H8O6S2
Molecular Weight:288.3

Naphthalene is mixed with 20 % oleum at 20 – 35 C followed by gradual addition of 65 % oleum and further naphthalene alternately. After heating for 6 h at 55 C the reaction mixture is added to water, and the product is precipitated as the free acid by cooling or as the disodium salt by the addition of alkaline sodium sulfate. In each case, the isolated yield is ca. 53 %. The 1,6-disulfonic acid can be recovered from the filtrate. Higher yields of 4 have been reported for alternative processes; for example, solvent sulfonation with sulfur trioxide and chlorosulfonic acid in a solvent such as tetrachloroethylene [24] or sulfonation with oleum through a double screw-feed apparatus.

91-20-3 Synthesis

91-20-3
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$13.19/250mg

81-04-9
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$5.00/25g

Yield:81-04-9 55%

Reaction Conditions:

with sulfuric acid at 30;

Steps:

1 (1) Sulfonation reaction
Add 180g of fuming sulfuric acid to the sulfonation pot, slowly add 75g of refined naphthalene, keep the temperature at 30 ° C for sulfonation reaction, react for 3-4 hours, and then slowly add 500g of fuming sulfuric acid.The sulfonation reaction was carried out at a temperature of 30 ° C for 3 hours.A solution of 1,5-naphthalenedisulfonic acid is obtained, the solid content is about 55%,The temperature was maintained at 160 to 162 ° C for 1.5 hours.

References:

Wujiangmei Yansan You Dyeing Liao Chemical Co., Ltd.;Zhang Zhengfu;Dong Zhitang;Xu Gang CN109535040, 2019, A Location in patent:Paragraph 0035; 0037; 0038

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1655-29-4 Synthesis