Preparation process for cresol red

Abstract

The invention specifically discloses a preparation process for cresol red, which belongs to the field of synthetic technology of indicators. The preparation process comprises the following steps: 1, with o-benzoyl sulfonic anhydride, o-benzoyl and zinc chloride anhydrous in a mass ratio of 1: 1-2: 1-2.5 as raw materials, controlling reaction temperature to be 100 to 110 DEG C and reaction time to be 3 to 4 h and adding hydrochloric acid and water with slow stirring so as to prepare a tiny particle; 2, subjecting the tiny particle prepared in the step 1 to filtration and deposition in warm water with a temperature of 45 to 60 DEG C; and 3, successively subjecting a sediment of filtration obtained in step 2 to heating, drying and cooling, adding diethyl ether and benzene, carrying out slow stirring for 15 to 30 m and carrying out filtration and drying so as to finally prepare cresol red. The preparation process for cresol red provided by the invention overcomes the problems of low efficiency and low purity of conventional processing and preparation technology, meets demands of middle and small-sized enterprises for synthesis technology and can rapidly and easily process and prepare cresol red with high purity.

Description

technical field [0001] The invention relates to the technical field of indicator synthesis, in particular to a preparation process for cresol red. Background technique [0002] As is well known, cresyl red (i.e. Phenol red or phenolsulfonylphthalein or phenolsulfonylphthalein) is a chemical reagent for acid-base testing, which produces a color change as the pH value of the solution changes during use, and is an indispensable synthetic reagent in the current chemical research field. [0003] The cresyl red that adopts prior art to process and prepare, the raw material consumption of its preparation is very big and processing equipment equipment is expensive, processing and production yield is low, quality is poor, and its reaction process is also more complicated and difficult to control, and then to a certain extent It also increases the input of the production cost of the enterprise, so how to improve the processing production efficiency and reduce the input of the product...

AI Technical Summary

Problems solved by technology

[0003] The cresyl red that adopts prior art to process and prepare, the raw material consumption of its preparation is very big and processing equipment equipment is expensive, processing and production yield is low, quality is poor, and its reaction process is also more complicated and difficult to control, and then to a certain extent It also increases the input of the production cost of the enterprise, so how to improve the processing production efficiency and reduce the input of the production cost of the enterprise is the main technical problem at present.