CS232629B1 - The method of homogeneously catalyzed oxidation of phenol by the oxygen - Google Patents

Abstract

The invention relates to a method of homogeneously catalyzed oxidation of phenol with dioxygen in a homogeneous phase in the presence of copper complexes in an acetonitrile environment. A solution of the composition Cu (I) Cl~-NO3'-phenol-acetonitrile with a Cu (I) concentration of 1.10~3 to 1.1CT1 mol. . dm-3, phenol 2.10~2 to 2.10"1 mol. dm-3 and molar ratio (Cu(I)j : [Cl-] : : [NOs-] in the range 1:1: 1 to 1: 8 : 8 is bubbled with dioxygen at 15 to 55 °C for over 10 minutes

Description

The invention relates to a process for the homogeneously catalyzed oxidation of phenol with oxygen.

A number of systems are known in which the oxidation of phenols with oxygen is carried out in the presence of the catalyst compounds described by Gampp (1981). In addition to a number of copper salts such as Cu (II) -multi complexes described by Hay (1959), Endres (1963), Finkbeiner (1966), Hewitt (1967), Demmin (1981), Cu (II) -morpholine described by Brackman (1955), The Cu (II) -aminocarbonate complexes described by Davies (1979) and others reported by Hutchings (1975) have also investigated some Cu (I) systems, such as CuCl in pyridine described by Demmin (1981) and Nishid (1982). The reaction products of the above oxidations were diphenoquinones, various polymers, or mixtures thereof. 3,3 ', 5,5'-tetramethyl-4,4'-diphenoquinone was the product of oxidation of 2,6-dimethylphenol with oxygen in the presence of Cu (NO 3 J 2 described) by Tsuruy (1977); addition of piperidine or diethylamine resulted in the formation of poly (2,6-dimethylphenylene oxide). An analogous polymer of poly (2,6-dibromophenylene oxide) is formed selectively by oxidizing 2,4,6-tribromophenol with oxygen in acetonitrile Cu (NO 3) 2 solution as described by Tsuruya (1975). p-benzoquinone was prepared by Beltram (1979) only by oxidation of phenol with oxygen in dimethylformamide, dimethylsulfoxide, 1,4-dioxane and ethylene glycol at a temperature of 50-110 ° C and an oxygen pressure of 35 kg / / cm ² in the presence of CuCl 2 as a catalyst.

These drawbacks are eliminated in the manner of homogeneously catalyzed oxidation of phenol in the homogeneous phase in the presence of medium complexes in acetonitrile medium, which is based on the Cu (I) -Cl-NO 3 phenol-acetonitrile solution having Cu (I) 1 concentrations. 10-3 to 1. 10 ¹ mol. dm ³ , phenol 2. ² to 2.10 ¹ mol. dm ³ and the molar ratio [Cu (I)]: [Cl]: [NO 3 -] = 1: 1: 1 to 1: 8: 8 is bubbled with oxygen at atmospheric pressure in a glass reactor at 15 ° C to 55 ° C over 10 minutes.

The essence of this process for the preparation of p-benzoquinone is the catalytic function of the complexes of the media formed in the Cu (I) -Cl-NO 3 -phenol-acetonitrile system. The formation of p-benzoquinone has the character of catalytic cycles, including phenoxide radicals, Cu (II) complexes, and activated oxygenate.

The advantages of the above process for the preparation of p-benzoquinone are, in comparison with the published procedures, mainly in the simplicity of design and thus without the need to construct reactors of special properties. The process is carried out under milder conditions at room temperature, atmospheric pressure of oxygen and the energy consumption of the reaction is lower. Affordable, inexpensive chemicals are used which do not need to be cleaned or treated in any way.

The subject matter of the invention is described in the examples without being limited thereto.

Example 1

In the preparation of the reaction mixture of the composition Cu (I-Cl-NO3-phenol-acetonitrile, starting from the chloride or nitrate medium to obtain a solution of the composition Cu (I) -X-acetonitrile (where X = Cl-NO3-) with (1) the first IO ¹ mol. ^dm-3. to this solution, the solid LiCl L1NO3 and phenol to the resulting solution, the concentration of Cu (I) ¹ 1.10 mol. ^dm-3, phenol second 10 ¹ mol. dm ³ and a molar ratio of [Cu (Ij] [Cl ^-] [NO3] = 1: 1: 1. the reaction mixtures the concentration of Cu (Ij of below 1.10 mol ^_1.. dm ^"3 was prepared by stirring of a Cu (I) -X-acetonitrile stock solution and pipetted volumes from LiCl stock solutions in LiCl 1 acetonitrile. 10 ² mol dm ^-3 or L1NO3 in acetonitrile with LiNO ² 1.O ² mol dm ^-3 . 50 cm ^{3 of the} thus prepared reaction mixture is then bubbled through oxygen-free glass reactor at 30 ° C + 1 ° C to isolate p-benzoquinone from the reaction mixture. and identified in the form of its 2,4-DNP adduct based on TLC and elemental organic analysis, melting points, γ spectra, and its concentration was determined by titration.

Example 2

The procedure was as in Example 1 except that the molar ratio in the resulting solution was [Cu (I) j: [Cl]: [NO 2 ^- ] = = 1: 8: 1, thereby increasing the yield of p-benzoquinone by 100 %.

SUBJECT

Claims (1)

A method of homogeneously catalyzed oxidation of phenol dikyslíkom in the homogeneous phase in the presence of a copper complex in an acetonitrile characterized in that the composition of the solution of Cu (I) Cl-No3 ^_ phenol acetonitrile, prepared from a stock solution of Cu (I) Cl ^- acetonitrile, the solid LiCl, LiNOs and phenol, or from a stock solution of Cu (I) -NO3-aceYNALEZ tonitrile, solid LiCl, L1NO3 and phenol so that the concentration of Cu (Ij is 1 10 ³ to 1. 10 ¹ mol dm ^-3 , phenol 2.10 ^-2 to 2.10 ¹ mol dm ^-3 and the molar ratio [Cu (Ij):: [Cl "]: [NO 3 -] ranging from 1: 1: 1 to 1: 8: 8 at 15 ° C to 55 ° C bubbled with oxygen for more than 10 minutes.