Process for production of iodine compounds and process for production of high-purity 5-iodo-2-methylbenzoic acid

Abstract

Provided is a production method for an iodine compound in which iodine is reacted with a substrate in the presence of a porous material having a pore diameter of 500 nm or less or in the presence of the above porous material and an oxidizing agent and a production process for high purity 5-iodo-2-methylbenzoic acid comprising an iodination reaction step carried out by the above-mentioned, a crystal precipitation and separation step in which a product is precipitated by adding water or cooling and then separated and a purification step in which crystal separated is recrystallized using an organic solvent. According to the production method for an iodine compound described above, iodine can be introduced into various substrates at a high selectivity. Since expensive metals and specific reagents do not have to be used, it can readily be carried out in an industrially scale, and the product having a high purity can be obtained. Further, the process comprising the iodination reaction, separation and purification steps described above makes it possible to readily obtain at a high yield, 5-iodo-2-methylbenzoic acid having a high purity which is useful in uses for functional chemical products such as medicines. The process of the present invention comprising iodination reaction, separation and purification steps is characterized by that it is simple in terms of a procedure and that the purification load is smaller, and it is very advantageous in industrially carrying out.

Description

Background of the invention [0001] The invention relates to a method for directly and selectively preparing iodine compounds using iodine, and a preparation process for high-purity 5-iodo-2-methylbenzoic acid. Iodine compounds are important compounds that are widely used as medicines such as contrast agents and therapeutic agents for thyroid diseases, hygienic materials for antifungal and antifungal purposes, electronic materials, optical functional materials, etchant, for life Catalysts and materials for chemical reactions in the fields of science, electro-, information-communication, environment and energy. And besides its use as pharmaceuticals and agricultural chemicals, high purity 5-iodo-2-methylbenzoic acid is a useful raw material for various performance chemicals. [0002] related technology [0003] Compounds containing fluorine or iodine atoms have characteristics not observed in other halogen-containing compounds. For example, fluorine atoms are small in size an...

AI Technical Summary

Problems solved by technology

Therefore, the problem involved therein is that product purity and isolation yields are compromised, however, no method to reduce the amount of regioisomer by-products is shown in any of the general methods shown above

A known method for regioselectively separating aromatic compounds is a method of reacting iodine monochloride in the presence of zeolite (Catalysis Letters, vol.40, p.257, 1996). methods of iodination (Japanese Patent Publication No. 219241 / 1984 and Japanese Patent Publication (by PCT) No. 502819 / 1989), however, none of them can keep the selectivity of the reaction at a satisfactory level, And there are almost no reaction examples of compounds containing electro-withdrawing groups such as 2-methylbenzoic acid