RU2342379C2 - Method of obtaining 2,5-diphenyl-3,4- fullero[60]tetrahydrothiophen - Google Patents

Abstract

FIELD: chemistry, pharmacology.

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

. Essence of method lies in interaction of fullerene C₆₀ with dibenzylsulfide in presence of catalyst hafnocene dichloride Cp₂HfCl₂ in toluol medium at temperature 140-160°C during 4-8 hours. Target product output is 42-64%.

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

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Description

The present invention relates to organic chemistry, specifically, to a method for producing 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (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], F. Effenberger, G. Grube. Synthesis, 1998, 1372-1379) for producing a fullerene derivative with a thiophene fragment of the formula (2) by reacting C ₆₀ with 2,3-bis (bromomethyl) thiophene in boiling toluene in the presence of a dehalogenating reagent consisting of crown ether and KI.

The known method does not allow to obtain 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1).

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 as a solvent at a temperature of 110 ° C according to the scheme:

The known method does not allow to obtain 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1).

Thus, in the literature there is no information on the selective synthesis of 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1).

A new method is proposed for producing 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1).

The essence of the method consists in the interaction of fullerene C ₆₀ with a dibenzyl sulfide of the formula (PhCH ₂ ) ₂ S in the presence of a hafnacene dichloride catalyst (Cp ₂ HfCl ₂ ), taken in a molar ratio of 0.01, respectively: (0.045-0.055) :( 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 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1) is (according to HPLC) 42-64%. The reaction proceeds according to the scheme:

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

2,5-Diphenyl-3,4-fullero [60] tetrahydrothiophene (1) is formed only with the participation of fullerene [60] and dibenzyl sulfide.

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 this reaction in the presence of a catalyst of hafnacenedichloride Cp ₂ HfCl ₂ more than 25 mol.% With respect to C ₆₀ does not significantly increase the yield of the target product (1). The use of a catalyst of the hafnacenedichloride Cp ₂ HfCl ₂ catalyst with 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 sites in the reaction mass.

A change in the ratio of the starting reagents towards a significant increase in the content of dibenzyl 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:

1. The proposed method is based on the use of dibenzyl sulfide and a catalyst Cp ₂ HfCl ₂ as a starting reagent. In the known method, bis (trimethylsilylmethyl) sulfoxide is used. The proposed method, unlike the known one, allows one to selectively obtain 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (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 in an argon atmosphere is placed 0.01 mmol of fullerene C ₆₀ , 10 ml of “dry” toluene, 0.05 mmol of dibenzyl sulfide and 0.002 mmol of catalyst Cp ₂ HfCl ₂ , stirred for 6 hours at a temperature of 150 ° C, get 2, 5-diphenyl-3,4-fullero [60] tetrahydrothiophene of the general formula (1) with a yield of 57% (according to HPLC).

¹³ C NMR spectrum of 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1) (δ, ppm): 65.36 (C ^2.5 ), 74.65 (C ^3.4 ), 146.41 (C ^6.12 ), 126.19 (C ^7.17 ), 128.67 (C ^{8.10.14, 16} ), 127.36 (C ^9.15 ), 127.53 (C ^11.13 ). The signals of the carbon atoms of the fullerene fragment are located in the region of 137-158 ppm.

Other examples confirming the method are given in table 1.

Table 1 No. p / p The molar ratio of C ₆₀ : (PhCH ₂ ) ₂ S: Cp ₂ HfCl ₂ , mmol The reaction temperature, ° C Reaction time, hour Yield (1),% one 2 3 four 5 one. 0.01: 0.05: 0.002 150 6 57 2. 0.01: 0.055: 0.002 150 6 60 3. 0.01: 0.045: 0.002 150 6 53 four. 0.01: 0.05: 0.0025 150 6 64 5. 0.01: 0.05: 0.0015 150 6 51 6. 0.01: 0.05: 0.002 160 6 59 7. 0.01: 0.05: 0.002 140 6 42 8. 0.01: 0.05: 0.002 150 8 61 9. 0.01: 0.05: 0.002 150 four 49

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

Claims (1)

The method of obtaining 2,5-diphenyl-3,4-fullero [60] tetrahydrothiophene (1)

by reacting fullerene C ₆₀ with a dibenzyl sulfide of the formula (PhCH ₂ ) ₂ S in the presence of a hafnacenedichloride catalyst taken in a molar ratio of C ₆₀ : dibenzyl sulfide: Cp ₂ HfCl ₂ = 0.01: (0.045-0.055) :( 0.0015-0, 0025), in toluene, at a temperature of 140-160 ° C for 4-8 hours