RU2283830C1 - Method for production of 1-hydroxy-2,3-[60]fullerocyclopentanecarboxylic acid ethyl ester - Google Patents

Abstract

FIELD: organic chemistry.

SUBSTANCE: invention relates to method for production of 1-hydroxy-2,3-[60]fullerocyclopentanecarboxylic acid ethyl ester of formula 1

, wherein n = 1-2. Claimed method includes reaction of fullerene[60] (C60) with triethylaluminum (AlEt₃) in C60:AlEt₃ molar ratio of 1:(25-35) in presence of Cp₂ZrCl₂ as catalyst in amount of 15-25 mol.% based on C60 in argon atmosphere, in toluene medium under atmospheric pressure and at room temperature for 8 hours followed by addition to reaction mass at -15°C copper chloride (CuCl) catalyst in amount of 15-20 mol % based on C60 and oxalic acid diethyl ester (EtO₂C-CO₂Et) in equimolar amount in relation to AlEt₃. Further reaction mass is agitated at room temperature followed by hydrolysis of reaction mass.

EFFECT: method for production of 1-hydroxy-2,3-[60]fullerocyclopentanecarboxylic acid ethyl ester with high yield.

1 tbl, 1 ex

Description

The present invention relates to the field of organic chemistry, specifically to a method for producing ethyl ester of 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid of the general formula (1):

, где n=1-2

where n = 1-2

Ethyl 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid of the formula (1) can be used in fine organic synthesis, in the production of physiologically active substances and drugs.

The known method ([1], Dzhemilev U.M., Ibragimov AG, Vostrikova OS, Vasilieva EV, Tolstikov GA Regioselective hydroalumination of unsaturated hydrocarbons catalyzed by zirconium complexes with alkylalanes. Izv. AN Ser. Chem., 1987, No. 5, 1089-1095) for the preparation of cyclopentanols, for example, 1,3-dimethyl-1- (hydroxymethyl) cyclopentane (2), by reacting 2,5-dimethyl-1,5-hexadiene with diisobutylaluminium chloride BuzAlCl) in the presence of a Cp ₂ ZrCl ₂ catalyst at a temperature of 40 ° C for 2 hours, followed by oxidation of the reaction mass with atmospheric oxygen according to the scheme:

In a known manner, 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester of formula (1) cannot be obtained.

The known method ([2], Dzhemilev U.M., Ibragimov A.G., Hafizova L.O., Borisova A.L., Tuktarov R.F., Abzalimov PP RF patent №2238262. BI No. 29 (2004) ) obtaining 2,3- [60] fullerocyclopentanols (3) by the interaction of fullerene-substituted cyclopentanes obtained by the interaction of fullerene [60] with AlEt ₃ and a Cp ₂ ZrCl ₂ catalyst with carboxylic acid esters in the presence of a CuCl catalyst according to the scheme:

In a known manner, 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester of formula (1) cannot be obtained.

A new method is proposed for the preparation of 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester of the formula (1).

The essence of the method consists in the interaction of fullerene C ₆₀ with triethylaluminium (AlEt ₃ ), taken in a molar ratio of C ₆₀ : AlEt ₃ = 1: (25-35), preferably 1:30, in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) in an amount 15-25 mol.% In relation to C ₆₀ , preferably 20 mol.%, In an argon atmosphere at room temperature (20-21 ° C) and atmospheric pressure in a toluene solution for 8 hours, followed by addition to the reaction mass at a temperature -15 ° С catalyst of copper chloride (CuCl) in an amount of 15-25 mol.% In relation to the initial fullerene [60], p preferably 20 mol%, and oxalic acid diethyl ether in an amount equimolar to AlEt ₃ , followed by stirring of the reaction mixture at room temperature (20-21 ° C.) for 6-10 hours, preferably 8 hours. Total ethyl ether yield 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid of the formula (1) after hydrolysis of the reaction mass is 50-69%.

The reaction proceeds according to the scheme:

Ethyl 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid of the formula (1) is formed only with the participation of AlEt ₃ , C ₆₀ and the zirconium catalyst Cp ₂ ZrCl ₂ . In the presence of other aluminum compounds (e.g. Bu ⁱ ₂ AlCl, Bu ⁱ ₃ Al, Bu ⁱ ₂ AlH, EtAlCl ₂ , Et ₂ AlCl) or other catalysts (e.g. Zr (acac) ₄ , ZrCl ₄ , Cp ₂ TiCl ₂ , Pd (acac) ₂ , Ni (acac) ₂ , NiCl ₂ , Fe (acac) ₂ ) the target product (1) is not formed.

Carrying out this reaction in the presence of a catalyst Cp ₂ ZrCl ₂ or CuCl more than 25 mol.% With respect to fullerene [60] does not lead to a significant increase in the yield of target products (1). The use of the catalyst Cp ₂ ZrCl ₂ or CuCl less than 15 mol.% Reduces the yield of the target products (1), which is probably associated with a decrease in catalytically active centers in the reaction mass. The reactions were carried out at room temperature (20-21 ° C). At a higher temperature (for example, 40 ° C), there is no significant increase in the yield of the target products (1), and at a lower temperature (for example, 0 ° C), the reaction rate decreases.

A change in the ratio of initial reagents in the direction of increasing their content relative to the initial fullerene [60] does not lead to a significant increase in the yield of the target product (1).

The reactions were carried out in toluene solution. In other solvents (e.g., ether), the reaction does not proceed.

Significant differences of the proposed method.

In the proposed method, oxalic acid diethyl ester is used as a starting reagent. In the known method, ethyl esters of carboxylic acids (formic, acetic, sorbic) are used as starting reagents.

The proposed method 6, in contrast to the known one, allows the preparation of 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester of the formula (1).

The method is illustrated by the following examples.

EXAMPLE 1. In a 250 ml glass reactor mounted on a magnetic stirrer in an argon atmosphere, 140 ml of dried toluene, 0.14 mmol of C ₆₀ , 0.028 mmol of catalyst Cp ₂ ZrCl ₂ , 4.2 mmol of AlEt _{3 are} placed, stirred for 8 hours at a temperature of 20-21 ° C, then at a temperature of -15 ° C, 0.028 mmol of CuCl catalyst and 4.2 mmol of oxalic acid diethyl ether are added, stirred for 8 hours at a temperature of 20-21 ° C and hydrolyzed with an ethereal HCl solution. 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester was isolated from the organic layer in 61% yield.

The spectral characteristics of 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid ethyl ester (1):

IR spectrum (ν, cm ^-1 ): 3400, 2950, 2870, 1700, 1610, 1460, 1380, 1310, 1180, 1100, 730, 700, 570, 530. ¹ H NMR spectrum (δ, ppm) ): 1.2 t (J = 7 Hz, 3H, CH ₃ ), 1.46 m (4H, CH ₂ ), 4.35 t (2H, CH ₂ -O-).

¹³ C NMR spectrum (δ, ppm, CDCl ₃ ): 13.83, 33.18, 38.01, 59.41, 66.39, 72.66, 96.31, 170.60. The signals of sp-2 carbon atoms of the fullerene sphere are in the region of 124.49-157.73.

Other examples confirming the method are shown in table 1.

Table 1 №№ The ratio of C ₆₀ : AlEt ₃ : Cp ₂ ZrCl ₂ : EtO ₂ C-CO ₂ Et: CuCl, mmol Total reaction time, hour The yield of ethyl ester of 1-hydroxy-2,3- [60] fullero-cyclopentanecarboxylic acid (1),% one. 0.14: 4.2: 0.028: 4.2: 0.028 16 61 2. 0.14: 4.9: 0.028: 4.9: 0.028 16 64 3. 0.14: 3.5: 0.028: 3.5: 0.028 16 55 four. 0.14: 4.2: 0.035: 4.2: 0.035 16 69 5. 0.14: 4.2: 0.021: 4.2: 0.021 16 fifty 6. 0.14: 4.2: 0.028: 4.2: 0.028 eighteen 67 7. 0.14: 4.2: 0.028: 4.2: 0.028 fourteen 57

The reactions were carried out at room temperature (20-21 ° C) in a solution of toluene in an argon atmosphere without access of light. In all experiments, the number of substituents in the fullerene molecule [60] varies from 1 to 2.

Claims (1)

The method of producing ethyl ester of 1-hydroxy-2,3- [60] fullerocyclopentanecarboxylic acid of the formula (1)

where n = 1-2, characterized in that the fullerene C ₆₀ is reacted with triethylaluminium (AlEt ₃ ) at a molar ratio of C ₆₀ : AlEt ₃ = 1: (25 ÷ 35) in the presence of a catalyst of zirconacenedichloride (Cp ₂ ZrCl ₂ ), taken in an amount of 15-25 mol. % with respect to C ₆₀ , in an argon atmosphere at room temperature and atmospheric pressure in toluene for 8 hours, followed by adding to the reaction mass at a temperature of -15 ° C a catalyst of copper chloride (CuCl) in an amount of 15-25 mol.% relative to C ₆₀ and oxalic acid diethyl ether (EtO ₂ C-CO ₂ Et) in equimolar to Al Et ₃ amount, after which the reaction mass is stirred at room temperature, followed by hydrolysis of the reaction mass.