A kind of process method for preparing 5-bromoisochroman-4-one without catalyst method

Abstract

The invention provides a technical method for preparing 5-bromoisochroman-4-one through a catalyst-free process. The technical method comprises the following steps: dissolving 5-bromoisochroman into an organic solvent; introducing oxygen into the organic solvent; and sealing a reactor, and carrying out a reaction at a high temperature; wherein the organic solvent is selected from the group consisting of n-hexane, n-heptane, n-octane and cyclohexane; the introduction amount of the oxygen is that the pressure of the oxygen in the reactor is 0.2 to 3 MPa; the temperature of the reaction is 120 to180 DEG C; and the time of the reaction is 2 to 40 h. According to the invention, the 5-bromoisochroman-4-one is prepared by using the 5-bromoisochroman and the oxygen as raw materials under the condition of no addition of any catalysts or additives. The method provided by the invention has the following advantages: generation of wastes in the production process is reduced; a finished product iseasier to be purified; the purity of the product is significantly improved; a reaction solvent can be recycled; thus, the cost of production is reduced; and environmental pollution is reduced.

Description

technical field [0001] The invention relates to the technical field of preparation of chemical raw materials, in particular to a process for preparing 5-bromoisochroman-4-one without a catalyst. Background technique [0002] Isochroman-4-one and its derivatives have the effects of lowering blood pressure, treating Alzheimer's disease, anti-inflammation, and anti-oxidation, and are widely used in the field of medicine ( Studies in Natural Products Chemistry , 1995, 15 , 381–422). Isochroman-4-ones and their derivatives can be efficiently synthesized by oxidation of the carbon-hydrogen bond in isochroman. In the early days, the oxidants used were usually sodium hypochlorite, tert-butyl hydroperoxide, transition metal oxides, etc. However, these oxidants have problems such as high cost and large pollution. Compared with these oxidants, oxygen is more favored by the industry. It not only has a lower cost, but also produces water as a by-product after oxidation, which has lit...

AI Technical Summary

Problems solved by technology

But the price of these catalysts or additives is higher, so that the production cost of isochroman-4-one is higher, which is not conducive to large-scale production and use

At the same time, the existence of the catalyst in the reaction system will also cause difficulties in the purification of the finished compound, and cause more waste in the reaction environment solvent, which cannot be recycled.

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