RU2430091C1 - Method of producing 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3 - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3 of general formula:

where 1) R₁=-CH₃; R₂=-CH=CHC₆H₅; 2) R₁=R₂=-CH=CHC₆H₅; 3) R₁=-CH₃; R₂=-CH=C(CH₃)₂, which can be used as extraction agents for nonferrous and platinum-group metals, as well as in medicine. The method is realised through reaction of ortho-phenylenediamine and the corresponding unsaturated ketone with molar ratio of components equal to 1:1, while heating in dry benzene for three hours in the absence of a condensing agent.

EFFECT: novel simple method of producing 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3, characterised by low production costs and high output of the desired product.

2 tbl, 1 ex

Description

A method for producing 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3 of the general formula

Where

1) R ₁ = —CH ₃ ; R ₂ = —CH = CHC ₆ H ₅ ;

2) R ₁ = R ₂ = —CH = CHS ₆ H ₅ ;

3) R ₁ = —CH ₃ ; R ₂ = —CH = C (CH ₃ ) ₂ .

The invention relates to organic chemistry and can be used in the synthesis of derivatives of benzocyclopentadiimines-1,3, which are used as extractants of non-ferrous and platinum metals, as well as physiologically active substances.

A known method for producing substituted benzimidazoles by the interaction of orthophenylenediamine with nitriles or aldehydes in the presence of copper (II) acetate [1] (R. Weidenhagen and G. Train, Ber., 1942, 75, 1936). At the same time, intolerance to the absence of widely applicable general methods for the synthesis of imidazoles and benzimidazoles has been noted in the literature [2] (M.R. Grimmet, Adv. Heterocycl. Chem., 1970, 12, 104).

Closest to the proposed method is the method of condensation of ortho-phenylenediamine with nitriles or aldehydes [1].

As a prototype, the condensation method closest in terms of starting materials [1] was selected due to the lack of a closer analogue to the method of producing benzocyclopentadiimines-1,3 proposed in this application. The main disadvantage of the prototype is the use of a condensing agent, copper acetate (II), which increases the cost and complicates the method. The disadvantages include the multi-operation method and the low yield for most products.

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, improving control over the process and obtaining a wide range of compounds that find extensive fields of application in organic chemistry, chemistry of non-ferrous and platinum metals, as well as medicine.

This goal is achieved by mixing equimolar amounts of ortho-phenylenediamine and unsaturated ketone and heating in dry benzene at the boiling point of benzene for three hours, with a molar ratio of components 1: 1.

Table 1 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3 No pp Compound formula Starting ketone T pl. ° C Bis hydrochloride T pl. ° C one

4-phenylbuten-3-one-2 (benzalacetone) 57-8 160-1 2

1,5-diphenylpentadiene-1,4-one-3 (dibenzalacetone) 85-6 153-4 3

2-methylpenten-2-one-4 (mesityl oxide) 95-6 145-6

table 2 Elemental analysis of 2,2-disubstituted-4,5-benzocyclopenta-1,3-diimines No. Connection Name Gross formula % FROM % N found calculated found calculated one 4,5-benzo-2-methyl-2- (phenylvinylylene) -cyclopentadiimin-1,3 C ₁₅ H ₁₆ N ₂ 80.11 80.32 6.93 7.19 2 4,5-benzo-2,2-bis- (phenyl-vinylene) -cyclopentadiimin-1,3 C ₂₂ H ₂₀ N ₂ 84.32 84.58 6.17 6.45 3 4,5-benzo-2-methyl-2- (iso-butenyl) -cyclopentadiimin-1,3 C ₁₁ H ₁₆ N ₂ 74.67 74.96 8.83 9.15

The method differs from the method selected as a prototype in that there is no condensing agent. The absence of a condensing agent is necessary because the condensation of ortho-phenylenediamine with unsaturated ketones in dry benzene proceeds under the influence of temperature, and a condensing agent is not needed. The specified difference from the prototype leads to the fact that the proposed method, with respect to many unsaturated ketones, becomes a general method for the synthesis of a wide range of heterocyclic compounds and can become an industrial method for their preparation due to the cheapness and simplicity of the method and the used plants.

Example (general methodology).

5 mmol of ortho-phenylenediamine and 5 mmol of ketone (see Table 1) are dissolved in 100 ml of dry benzene. The solution is heated at the boiling point of benzene for three hours. Benzene is distilled off on a rotary evaporator in vacuo (65 mm Hg). The crystalline product is washed twice with hexane and dried. The yield of substances is quantitative. The melting points of the obtained compounds are presented in table 1. The systematic names of the products and analyzes of these compounds are presented in Table 2 under the same numbers as in Table 1. For all substances, salts with hydrochloric acid were obtained: bis-hydrochlorides, the melting points of which are given in Table 1

Claims (1)

The method of obtaining 2,2-disubstituted-4,5-benzo-cyclopentadiimines-1,3 of the General formula

where
1) R ₁ = —CH ₃ ; R ₂ = —CH = CHC ₆ H ₅ ;
2) R ₁ = R ₂ = —CH = CHC ₆ H ₅ ;
3) R ₁ = —CH ₃ ; R ₂ = —CH = C (CH ₃ ) ₂ ,
characterized in that the method is carried out by the interaction of ortho-phenylenediamine and the corresponding unsaturated ketone with a molar ratio of components of 1: 1 when heated in dry benzene for three hours and in the absence of a condensing agent.