Synthesis process for cosmetic-grade 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid

Abstract

The invention discloses a synthesis process for cosmetic-grade 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid. The synthesis process comprises the following process steps: adding 2-hydroxy-4-methoxybenzophenone and a solvent into an enamel reaction vessel; then adding chlorosulfonic acid drop by drop under protection of nitrogen with stirring; controlling the temperature of the materials in the reaction vessel to be 26 to 35 DEG C through jacket water-bath cooling and controlling of the addition speed of chlorosulfonic acid and carrying out a reaction for 20 to 25 h; after completion of the reaction, subjecting a product of the reaction to centrifugal filtering and separation; and washing the product with a corresponding solvent and then drying the product under the protection of nitrogen. A hydrogen chloride by-product is recovered from a HCl recovery packed tower and used for preparation of an aqueous hydrochloric acid solution with a concentration of 20 to 30%; a solid alkali packed tower is used for neutralizing a small amount of hydrogen chloride gas in tail gas; a solvent distillation recovery system employs a normal pressure distillation column for distillation recovery of the solvent; and 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid are recovered from raffinate in the bottom of the vessel.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis, and in particular relates to a cosmetic-grade 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid synthesis process. Background technique [0002] The synthesis process of cosmetic grade 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid at least includes drying, washing, centrifuging, filtering and other processes. In the current 2-hydroxyl-4-methoxybenzophenone-5-sulfonic acid synthesis process method, the technological process is not easy to implement, and the generated 2-hydroxyl-4-methoxybenzophenone-5- The finished product of sulfonic acid has low purity, low single-pass conversion rate of reactants, complex production process, low production efficiency and high cost, and is not suitable for large-scale production. Contents of the invention [0003] In order to overcome the above-mentioned technical problems existing in the prior art field, the object of the present invention is ...

AI Technical Summary

Problems solved by technology

In the current 2-hydroxyl-4-methoxybenzophenone-5-sulfonic acid synthesis process method, the technological process is not easy to implement, and the generated 2-hydroxyl-4-methoxybenzophenone-5- The finished product of sulfonic acid has low purity, low single-pass conversion rate of reactants, complex production process, low production efficiency and high cost, and is not suitable for large-scale production