RU2315047C1 - Method for preparing 8-ethyl-6,7-fullero[60]-3-oxa-8-azabicyclo[3.2.1]octane - Google Patents

Abstract

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of 8-ethyl-6,7-fullero[60]-3-oxa-8-azabicyclo[3.2.1]octane of the general formula (1):

. Method involves interaction of fullerene[60] with N-ethylmorpholine in the mole ratio fullerene-C₆₀ : N-ethylmorpholine = 0.01:(0.01-0.011) in the presence of Cp₂TiCl₂ as a catalyst taken in the amount 15-25 mole% with respect to fullerene[60], in toluene medium as a solvent at temperature ~20°C for 18-30 h. The yield of the end product is 73-90%. Synthesized compound can be used as chelating agent, sorbent, biologically active compound and in creature of novel materials with desired electronic, magnetic and optical properties.

EFFECT: improved method of synthesis.

1 tbl, 1 ex

Description

The present invention relates to organic chemistry, specifically to a method for producing 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane of the general formula (1):

Functionally substituted fullerenes can be used as complexing agents, sorbents, biologically active compounds, as well as in the creation of new materials with specified electronic, magnetic and optical properties.

A known method ([1], Zheng Dagui, Li Yuliang, Yang Jingkui, Zhu Daoben. Fulleren Sci. And Technol., 1996, v.4, No. 5, 1067-1072) to obtain a pyrrolidine derivative of fullerene [60] of the formula (2) the reaction of C ₆₀ s (HCO) _n and DL-valine in a toluene solution at the boiling point of the solvent (~ 110 ° C) in a nitrogen atmosphere with a yield of 45%.

The known method does not allow to obtain 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1).

A known method ([2], GELawson, A. Kitaygorodskiy, B. Ma, CE Bunker, Y.-P. Sun. J. Chem. Soc., Chem. Commun., 1995, 21, 2225-2226) to obtain a pyrrolidine derivative of fullerene [60] of formula (4) by the reaction of photocycloaddition of triethylamine (3) to C ₆₀ in toluene at 20 ° C in a nitrogen atmosphere with a yield of 32% according to the scheme.

In a known manner, 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1) cannot be obtained.

Thus, there is no information in the literature on the selective synthesis of 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1).

A new method is proposed for producing 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1).

The essence of the method consists in the interaction of fullerene [60] with N-ethylmorpholine (5), taken in a molar ratio of 0.01: (0.01-0.011), preferably 0.01: 0.0105, in the presence of a titanium catalyst Cp ₂ TiCl ₂ in an amount of 15-25 mol. % with respect to fullerene [60], at room temperature (~ 20 ° C), for 18-30 hours, preferably 24 hours, in toluene solution. The yield of 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1) is 73-90% (HPLC). The reaction proceeds according to the scheme:

N-ethylmorpholine (5) is taken in excess with respect to fullerene [60] in order to increase the yield of the target product (1). The decrease in the amount of N-ethylmorpholine (5) with respect to C _{60 is} impractical, since it leads to a sharp decrease in the yield of the target product.

8-Ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1) is formed only with the participation of fullerene [60] and N-ethylmorpholine (5).

Carrying out this reaction in the presence of a titanium catalyst Cp ₂ TiCl ₂ more than 25 mol.% With respect to C ₆₀ does not lead to a significant increase in the yield of the target product (1). The use of the catalyst Cp ₂ TiCl ₂ less than 15 mol.% With respect to C ₆₀ reduces the yield of the product (1), which is possibly associated with a decrease in the catalytically active centers in the reaction mass.

A change in the ratio of the starting reagents in the direction of a significant increase in the content of N-ethylmorpholine (5) with respect to fullerene [60] leads to the addition of additional pyrrolidine fragments to the C ₆₀ molecule and a decrease in the selectivity of the reaction.

Significant differences of the proposed method:

1. The proposed method is based on the use of N-ethylmorpholine (5) as a starting reagent; the reaction proceeds under the influence of a Cp ₂ TiCl ₂ catalyst. In the known method, triethylamine is used, the reaction proceeds by photo-irradiation. The proposed method, in contrast to the known one, allows the introduction of a pyrrolidine moiety with a morpholine substituent into a fullerene molecule to obtain 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1), the synthesis of which is not described in the literature.

The method is illustrated by the following examples:

EXAMPLE 1. In a 50 ml glass flask, 0.01 mmol of fullerene [60], 10 ml of “dry” toluene, 0.0105 mmol of N-ethylmorpholine (5) and 0.002 mmol of Cp ₂ TiCl ₂ catalyst are placed, stirred for 24 hours at a temperature of 20 ° C, get 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane of the general formula (1) with a yield of 84% (according to HPLC).

¹³ C NMR spectrum of 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane (1) (δ, ppm):

¹³ C NMR spectrum (δ, ppm): 14.22 (C ¹⁰ ), 44.93 (C ⁹ ), 61.57 (C ^1.5 ), 66.75 (C ^2.4 ), 71.63 (C ^6.7 ). The signals of the carbon atoms of the fullerene fragment are located in the region 136.88-137.66.

Other examples confirming the method are given in table 1.

Table 1 №№

:Cp₂TiCl₂, ммольMolar ratio, C ₆₀ :

: Cp ₂ TiCl ₂ , mmol Reaction time, h Yield (1),% one 2 3 four one. 0.01: 0.0105: 0.002 24 84 2. 0.01: 0.011: 0.002 24 87 3. 0.01: 0.01: 0.002 24 80 four. 0.01: 0.0105: 0.0025 24 90 5. 0.01: 0.0105: 0.0015 24 73 6. 0.01: 0.0105: 0.002 thirty 88 7. 0.01: 0.0105: 0.002 eighteen 77

Toluene was used as a solvent, since it has the highest solubility of fullerene [60]; reactions were carried out at room temperature (~ 20 ° С).

Claims (1)

The method of producing 8-ethyl-6,7-fullero [60] -3-oxa-8-azabicyclo [3.2.1] octane of the general formula (1)

characterized in that fullerene [60] interacts with N-ethylmorpholine in a molar ratio of C ₆₀ : N-ethylmorpholine equal to 0.01: (0.01-0.011), in the presence of a Cp ₂ TiCl ₂ catalyst in an amount of 15-25 mol. % with respect to fullerene [60], in toluene as a solvent at a temperature of ~ 20 ° C for 18-30 hours