RU2214413C2 - Method for preparing phenylene- and naphthylene phosphoric acids - Google Patents

Abstract

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method for preparing phenylene- and naphthylene phosphoric acids that can be used as extractants of uranium, nonferrous metals, insecticides and other biologically active substances. Invention describes method for preparing phenylene- and naphthylene phosphoric acids of the general formula:

Description

 The invention relates to the field of organic chemistry and can be used in the synthesis of aryl-substituted phosphoric acids, which are used as extractants of uranium and non-ferrous metals, as well as insecticides and other biologically active substances.

 There is a method of producing phosphoric acid esters by direct esterification of phosphoric acid with long carbon chain alcohols; for lower alcohols, alcohol is dehydrated with phosphoric acid. Another way - the interaction of alcohols with phosphorus pentoxide - leads to a mixture of monoalkyl and dialkyl phosphates [1. D. Purdela, R. Valchanu. Chemistry of organic phosphorus compounds. M .: Chemistry, 1072. C. 406]. In the aromatic series, this reaction has not found application. Known methods for producing esters of phosphoric acid from esters of pyrophosphorous acid; as well as from alcohols, or phenols and phosphorus oxychloride [2. V.M. Plec. Organic phosphorus compounds. M .: Oborongiz, 1940. S. 98 and 280].

 Closest to the proposed method is the method of esterification in the presence of phosphorus pentoxide [1], which has not yet been used to obtain aromatic esters of phosphoric acid.

 As a prototype, we have chosen the method of esterification closest in terms of starting materials [1]. The main disadvantage of the prototype is the formation of a mixture of products, namely, monoalkyl and dialkyl phosphates. Another disadvantage of the prototype is the lack of synthesis conditions for a number of aromatic hydroxy compounds: phenols and naphthols.

 The aim of the invention is to reduce labor costs by simplifying the method, reducing the cost of starting materials, increasing the speed of the process and the yield of products, and obtaining a wide range of compounds that find extensive applications in organic chemistry and chemistry of extraction processes.

 This goal is achieved by mixing equimolar amounts of phosphorus pentoxide and ortho-dihydroxyaromatic compounds (substituted by 1,2-dihydroxybenzenes and 2,3-dihydroxy-naphthalenes) and heated without moisture at a given temperature. The esterification product is purified by extraction into a benzene solution, followed by distillation of benzene. The method differs from the method selected as a prototype in that an individual product is formed, and not a mixture of compounds; during the synthesis process, neither solvents nor other auxiliary reagents are required. The absence of a mixture of substances in the product is due to the fact that, in contrast to alcohols, in one molecule of the ortho-dihydroxyaromatic compound there are two adjacent hydroxyl groups that both react simultaneously (under given conditions) and the possibility of the formation of a mixture of aromatic phosphates is unlikely. The absence of solvent in the synthesis process is necessary because different and sufficiently high temperatures are required for each individual product. In general, all these differences from the prototype lead to the fact that the proposed method becomes a general method for the synthesis of a wide range of compounds, and because of its simplicity it can become an industrial method for their preparation.

 Example (General methodology).

 Place 0.01 M of the dihydroxy compound shown in Table 1 and 0.01 M of phosphorus pentoxide in a round bottom flask, close it with a calcium chloride tube and mix the starting materials thoroughly. The mixture is heated for 1 hour at the temperature indicated in table 1. It is not necessary to warm above the indicated temperatures, because substances turn black and product yield decreases. After cooling the mixture, the product is extracted three times with dry benzene under reflux. Benzene is distilled off in a vacuum of a water-jet pump, under the same conditions, the substance is dried by heating in a water bath. The bulk of the substance is extracted with the first portion of benzene, with a threefold extraction, the product yield is close to quantitative. Table 1 shows the melting points of the products and formulas of the compounds. The systematic names and analyzes of these compounds are presented in table 2 under the same numbers as in table 1.

Claims (1)

A method of producing phenylene and naphthylene phosphoric acids of the general formula

where R is phenylene; 4-bromophenylene; 4-cyclohexylphenylene; 2,3-naphthylene; 1,6-dibromo-2,3-naphthylene,
characterized in that the method is carried out by the interaction of phosphorus pentoxide and the corresponding substituted 1,2-dihydroxybenzene or 2,3-dihydroxy-naphthalene with a molar ratio of components of 1: 1 and when heated in the temperature range from 180 to 230 ^o C for one hour.

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