RU2342376C2 - Method of obtaining 2-alkyl-5-phenyl-3,4- fullero[60]tetrahydrothiophenes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: claimed invention relates to field of organic chemistry, namely to method of obtaining 2-alkyl-5-phenyl-3,4- fullero[60]tetrahydrothiophenes of formula (I)

. Essence of method lies in interaction of fullerene C₆₀ with alkylbenzylsulfides in presence of catalyst Cp₂ZrCl₂ in toluol medium at temperature 140-160°C during 4-8 hours. Target product output is 42-70%.

EFFECT: obtaining compounds, which can be used as complex-forming agents, sorbents, biologically active compounds, as well as in creation of novel materials with set electronic, magnetic and optical properties.

1 tbl, 11 ex

Description

The present invention relates to organic chemistry, specifically to a method for producing 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes of the general formula (1):

where R = H, Me, Et

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], DMGuldi, S. Gonzalez, N. Martin, A. Anton, J. Green, J. Orduna. J. Org. Chem., 2000, 65, 1978-1983) to obtain heteroatom-containing derivatives of fullerene, and namely, 3- [3-tris (methylthio) tetrathiafulvalenylthiopropyl] triazolino [4,5: 1.2] - [60] fullerene of the formula (2) by reaction of C ₆₀ with 3- [3-tris (methylthio) tetrathiavulienylthiopropyl] triazide in o-dichlorobenzene.

In a known manner, 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes (1) cannot be obtained.

A known method ([2], H. Ishida, K. Itoh, M.Ohno. Tetrahrdron, 2001, 57, 1737-1747) for preparing fullerotetrahydrothiophene of formula (3) by the reaction of addition of bis (trimethylsilylmethyl) sulfoxide to C ₆₀ in o-dichlorobenzene at a temperature of 110 ° C according to the scheme:

The known method does not allow to obtain 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes (1). Thus, in the literature there is no information on the selective synthesis of 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes (1).

A new method is proposed for producing 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes of the general formula (1).

The essence of the method consists in the interaction of fullerene C ₆₀ with alkylbenzyl sulfides of the general formula RCH ₂ SPh (where R = H, Me, Et) in the presence of a zirconacene dichloride catalyst (Cp ₂ ZrCl ₂ ), taken in a molar ratio of 0.01: (0.045-0.055), respectively :( 0.0015-0.0025), preferably 0.01: 0.05: 0.0020, at a temperature of 140-160 ° C for 4-8 hours in a toluene solution. The yield of 2-alkyl-5-phenyl-3,4-fullero [60] -tetrahydrothiophenes of the formula (1) is (according to HPLC) 42-70%. The reaction proceeds according to the scheme:

Alkylbenzyl sulfide is taken in excess with respect to fullerene C ₆₀ in order to increase the yield of the target product (1). The decrease in the number of alkylbenzyl sulfide with respect to C _{60 is} impractical, since it leads to a decrease in the yield of the target product.

2-Alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes (1) are formed only with the participation of fullerene [60] and alkylbenzyl sulfides.

Carrying out the reaction at a higher temperature, for example 200 ° C, leads to the formation of compaction products. At lower temperatures, for example 100 ° C, the reaction rate decreases.

Carrying out the specified reaction in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl 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 ZrCl 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 catalytically active centers in the reaction mass.

A change in the ratio of the starting reagents towards a significant increase in the content of alkylbenzyl sulfide with respect to fullerene [60] leads to the addition of additional molecules of the starting sulfide to the C ₆₀ molecule.

Significant differences of the proposed method

The proposed method is based on the use of alkylbenzyl sulfides and a catalyst Cp ₂ ZrCl ₂ as a starting reagent. In the known method, bis (trimethylsilylmethyl) sulfoxide is used. The proposed method, unlike the known one, allows one fragment of the starting alkylbenzyl sulfide to be selectively introduced into the fullerene molecule to obtain 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes (1), the synthesis of which is not described in the literature.

The method is illustrated by the following examples.

EXAMPLE 1. In a metal autoclave with a volume of 17 ml, 0.01 mmol of fullerene C ₆₀ , 10 ml of “dry” toluene, 0.05 mmol of methylbenzyl sulfide and 0.002 mmol of catalyst Cp ₂ ZrCl _{2 are} placed, stirred for 6 hours at a temperature of 150 ° C., 2-phenyl-3 is obtained , 4-fullero [60] tetrahydrothiophene (Ia) with a yield of 60% (according to HPLC).

¹³ C NMR spectrum of 2-phenyl-3,4-fullero [60] tetrahydrothiophene (Ia) (δ, ppm):

65.42 (C ² ), 74.58 (C ^3.4 ), 63.20 (C ⁵ ), 146.43 (C ⁶ ), 126.56 (C ⁷ ), 128.69 (C ^8.10 ), 127.28 (C ⁹ ), 127.57 (C ¹¹ ) The signals of the carbon atoms of the fullerene fragment are located in the region of 130-161 ppm.

Other examples confirming the method are given in table 1

Table 1 №№ RCH ₂ SPh Molar ratio, C ₆₀ : RCH ₂ SPh: Cp ₂ TiCl ₂ , mmol The reaction temperature, ° C Reaction time, h Yield (1),% one 2 3 four 5 6 one. R = H 0.01: 0.05: 0.002 150 6 60 2. 0.01: 0.055: 0.002 150 6 64 3. 0.01: 0.045: 0.002 150 6 56 four. 0.01: 0.05: 0.0025 150 6 70 5. 0.01: 0.05: 0.0015 150 6 53 6. 0.01: 0.05: 0.002 140 6 67 7. 0.01: 0.05: 0.002 160 6 42 8. 0.01: 0.05: 0.002 150 8 63 9. 0.01: 0.05: 0.002 150 four 49 10. R = Me 0.01: 0.05: 0.002 150 6 55 eleven. R = Et 0.01: 0.05: 0.002 150 6 fifty

Toluene was used as a solvent, since it has a high solubility of fullerene C ₆₀ .

Claims (1)

The method of obtaining 2-alkyl-5-phenyl-3,4-fullero [60] tetrahydrothiophenes of the General formula (1)

where R = H, Me, Et, by reacting C ₆₀ fullerene with alkylbenzyl sulfides of the formula RCH ₂ SPh (where R = H, Me, Et), in the presence of a Cp ₂ ZrCl ₂ zirconacene dichloride catalyst, taken in a C ₆₀ : alkylbenzyl sulfide molar ratio: Cp ₂ ZrCl ₂ = 0.01 :( 0.045-0.055) :( 0.0015-0.0025), in toluene, at a temperature of 140-160 ° C for 4-8 hours.