RU2164233C1 - Method of preparing chloroaluminium phthalocyanine - Google Patents

Abstract

FIELD: medicine, more particularly preparation of colorants used in quantium electronics and preparation of medicinal agent used in photodynamic therapy of matignant neoplasms. SUBSTANCE: method comprises reacting, phthalonitrile and aluminium chloride. Aluminium chloride is previously treated with C₁-C₁₀ alcohol, and the resulting mixture is then heated with phthalonitrile at temperatures from 160 to 210 C. Method eliminates use of high-boiling organic solvents, prevents chlorination into macroring and makes it possible to prepare chloroaluminium phthalocyanine without hydroxide impurity with high yield. EFFECT: more efficient preparation method. 5 ex

Description

 The invention relates to basic organic synthesis, in particular it relates to a method for producing phthalocyanine of chloroaluminum, which can be used as a dye, pigment; as an intermediate for the preparation of dyes used in quantum electronics, as well as for the production of the Photosens drug, which is used for the photodynamic therapy of malignant neoplasms [E. Lukyanets - Grew up. Chem. J., t. 42, N 5, p. 9].

A known method of producing phthalocyanine of chloralumin from phthalonitrile and aluminum chloride by heating them at 250 ^o C without solvent [Moser FH, Thomas AL - Phthalocyanine compounds. Reinhold Publ., 1963. P. 123], however, in this case, chlorination of the phthalocyanine to the macro ring with the formation of chlorophthalocyanine of chloroaluminium is observed. To prevent chlorination in the macro ring, the interaction of phthalonitrile and aluminum chloride can be carried out in a mixture with sodium sulfate [for example, British Patent 552.124 (1943)], however, in this case, the mixture must be heated at high temperature (250-270 ^o C) and then removed from the reaction mixtures of significant quantities of salts.

 Closest to the proposed method, the technical solution is a method for producing aluminum chlorophthalocyanine described in [Moser F.H., Thomas A. L. - The phthalocyanines. CRS Press, 1983. V. 2. P. 4], where the production of aluminum phthalocyanine is carried out by the interaction of aluminum chloride and phthalonitrile in an organic solvent - trichlorobenzene. Firstly, the described method is inconvenient due to the use of a high-boiling solvent that is not miscible with water, since further purification is carried out by boiling in an aqueous acidic medium. Thus, it is necessary to expend other organic solvents and dry the product before further processing. Secondly, it is indicated that (and this is most essential), most likely, the product is a mixture of two substances - phthalocyanine chloraluminium and phthalocyanine hydroxyaluminium.

 The objective of the invention was to develop such a method that would ensure the production of phthalocyanine chloraluminium without impurities of aluminum phthalocyanine hydroxide and chlorination products in the macro ring, while being quite effective and technologically advanced.

Приведенные ниже примеры иллюстрируют предлагаемое изобретение.The problem was solved by pretreating aluminum chloride with C ₁ -C ₁₀ alcohols, followed by heating the resulting mixture at a temperature of 160-210 ^o C, which led to the production of phthalocyanine chloraluminium in high yield and purity. When carrying out the process at a temperature below 160 ^o C the formation of the complex does not occur. The process at a temperature above 210 ^o C is not technologically advanced. The following is a reaction scheme:

The following examples illustrate the invention.

Example 1. Obtaining phthalocyanine chloralumin
13.3 g of aluminum chloride are dissolved in 45 ml of ethanol, 43 g of phthalonitrile are added with stirring and, while stirring, the reaction mixture is heated in a bath with a temperature of 210 ^o C for 30 minutes. Then the melt is cooled to 90 ^o C, stirred at this temperature with 250 ml of 10% hydrochloric acid for 30 minutes, the resulting suspension is filtered, the precipitate is re-treated with hydrochloric acid, washed with water, then washed with hot acetone and dried. Obtain 32 g (68%) of phthalocyanine of chloroaluminium with a content of the main substance of ~ 99%, according to the NMR spectrum of ¹ N. Found,%: C1 5.93. C ₃₂ H ₁₆ AlClN ₈ . Calculated,%: C1 6.17. λ $\genfrac{}{}{0ex}{}{\text{Q}}{\text{m}}$ _ax, nm (ε _mol, L (mol · cm)) in H ₂ SO ₄ (conc.): 805 (234,000), in dimethyl sulfoxide: 676 (211,000).

 Dissolve 1 g of the obtained chloroaluminum phthalocyanine in 10 ml of concentrated sulfuric acid, stir the solution at room temperature for 2 hours and pour on 100 g of ice. The precipitate is filtered off, washed with water and boiled with 10% potassium hydroxide. After washing with water, washing with hot ethanol and drying, hydroxyaluminum phthalocyanine is obtained, which, according to elemental analysis, does not contain chlorine in the molecule.

Example 2
Chloraluminium phthalocyanine is prepared analogously to example 1, using butanol instead of ethanol. The yield was 57%.

Example 3
Chloraluminium phthalocyanine is prepared analogously to Example 1, using isoamyl alcohol instead of ethanol. The yield was 54%.

Example 4
Chloraluminium phthalocyanine is obtained analogously to example 1, using methanol instead of ethanol. The yield was 31%.

Example 5
Chloraluminium phthalocyanine is prepared analogously to example 1, using octanol instead of ethanol. The yield was 49%.

 Thus, the proposed method eliminates the use of high-boiling organic solvents, prevents chlorination in the macro ring, and provides phthalocyanine of chloroaluminium without an admixture of hydroxide with a sufficiently high yield. The developed method can be recommended for industrial development.

Claims (1)

A method of producing phthalocyanine of chloroaluminium by the interaction of phthalonitrile and aluminum chloride, characterized in that the aluminum chloride is pretreated with C ₁ - C ₁₀ alcohol and then the resulting mixture with phthalonitrile is heated at 160 - 210 ° C.