Etamsylate synthesis

Yield:2624-44-4 85%

Reaction Conditions:

in cyclohexane at 65 - 70;Solvent;Temperature;

Steps:

1; 2; 3 Example 3
To a 10 L enamel reactor was added 1.65 kg of hydroquinone, 4.5 L of cyclohexane, and 0.2 L of propionic acid.The mixture was heated to reflux with stirring, and refluxed for 2 h.After the water is separated, the temperature is lowered to micro reflux, and the internal temperature of the reactor is 85 ° C.Add 2.28kg concentrated sulfuric acid, control the internal temperature of the reaction kettle does not exceed 90 ° C;After the addition, the temperature was maintained at 90 ° C for 60 min.Stop heating, pass the cooling water to cool down to the lower paste temperature 65 ° C,A mixture of 1.25 kg of diethylamine and 0.9 L of water was added dropwise.Control the internal temperature of the reaction vessel to be added dropwise at 65 ° C, and the maximum height of the reaction vessel should not exceed 70 ° C;After the completion of the dropwise addition, the temperature is raised to 70 ° C to stir and dissolve the lower aqueous phase, and the hot liquid is separated;The aqueous phase was collected, transferred to a 10 L reaction kettle, slowly cooled to about 10 ° C, stirred and decanted for 1 h, then cooled to 5 ° C, stirred and decanted for 8 h, then centrifuged for centrifugation, centrifuged to dryness and then filtered cake with 1.5 L. Washing with propanol, 1.5L of isopropanol each time, a total of three times of beating,The white crystalline particulate solid phenolsulfonamide was obtained in an amount of 3.35 kg, the yield was 85%, and the purity was 99.89%. The obtained phenolsulfonamide was analyzed by high performance liquid chromatography, and the results obtained are shown in Fig. 4.

References:

Chengdu Pinghe Good Health Pharmaceutical Technology Co., Ltd.;Jin Lei;Lu Jie;Ni Ying;Zhang Ling;Zhang Weiqun CN109467522, 2019, A Location in patent:Paragraph 0025; 0029-0036

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