RU2368606C2 - Method of obtaining 6-thiaspiro[3,4]octane - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of obtaining 6-thiaspiro[3,4]octane can be used in fine organic synthesis, in production of oil additives and biologically active substances. The method involves reacting methylenecyclobutane with triethylaluminium (AlEt₃) in the presence of a catalyst in an argon atmosphere at room temperature and atmospheric pressure in hexane for 4 hours with subsequent addition to the reaction mass at temperature -40°C of thionyl chloride, taken in equimolar amount with respect to AIEt₃ and stirring at that temperature for 6-8 hours.

EFFECT: output of the desired product after hydrolysis of the reaction mass is 53-74%.

1 tbl, 7 ex

Description

The present invention relates to organic chemistry, in particular to a method for producing 6-thiaspiro [3,4] octane of the formula (1).

The specified compound can find application in fine organic synthesis, the production of highly effective anti-seize and anti-wear additives for oils, biologically active substances.

A known method (Dzhemilev U.M., Ibragimov A.G., Zolotarev A.P., Khalilov L.M., Musloukhov PP Synthesis and transformation of metalcycles. Message 9. Synthesis of polycyclic aluminocyclopentanes with the participation of (η ⁵ -C ₅ H ₅ ) ₂ ZrCl _2. Izv. AN Ser. Khim., 1992, No. 2, 386-391) for the preparation of tricyclic thiolans, for example, 3-thiatetracyclo [5.2.1.0 ^2,6 ] decane by the interaction of norbornene with AlEt ₃ under the action of 3-5 mol% catalyst Cp ₂ ZrCl ₂ in hydrocarbon solvents, or without solvent at a temperature of 25 ° C for 12-14 hours, followed by addition of slurry threefold excess relative AlEt ₃ elemental sulfur in benzene and maintaining the reaction mixture for 8 hours in refluxing benzene at ~ 80 ° C. The reaction proceeds according to the scheme:

In a known manner, 6-thiaspiro [3,4] octane of the formula (1) cannot be obtained.

The known method (Nikishin G.I., Zheludeva V.I., Lavrinovich L.I., Demchuk D.V., Troyansky E.I., Bubnov Yu.N. Izv. AN SSSR. Ser. Chem., 1989, No. 9, 2155-2156) for the preparation of 5,5-di (n-propyl) -6-thiaspiro [3,4] octane (4) by intramolecular cyclization of homoallyl mercaptan (3) under the action of the Pr ₃ BO ₂ -CH ₃ OH system according to the scheme :

In a known manner, 6-thiaspiro [3,4] octane of the formula (1) cannot be obtained.

Thus, in the literature there are no methods for the selective preparation of 6-thiaspiro [3,4] octane of formula (1).

A new method is proposed for producing 6-thiaspiro [3,4] octane (1).

The essence of the method consists in the interaction of methylene cyclobutane with triethylaluminum (Et ₃ Al) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ), taken in a molar ratio:

methylenecyclobutane: Et ₃ Al: Cp ₂ ZrCl ₂ = 10: (10-14) :( 0.4-0.6), preferably 10: 12: 0.5, in an argon atmosphere at room temperature (20-21 ° C) and atmospheric pressure in aliphatic solvent (hexane) for 4 hours, followed by cooling the reaction mass to -40 ° C, adding thionyl chloride (SOCl ₂ ), taken in an amount equimolar to AlEt ₃ , and stirring at this temperature for 6-8 hours, preferably 7 o'clock. The yield of 6-thiaspiro [3,4] octane is 53-74%. The reaction proceeds according to the scheme:

,

,

, EtAlCl₂, Et₂AlCl), других непредельных соединений (α-олефины, диены, ацетилены) или других катализаторов (например, Zr(acac)₄, ZrCl₄, Cp₂TiCl₂, Pd(acac)₂, Ni(acac)₂, NiCl₂, Fe(acac)₂) целевой продукт (1) не образуется.6-Tiaspiro [3,4] octane (1) is formed only with the participation of AlEt ₃ , methylene cyclobutane and a zirconium catalyst Cp ₂ ZrCl ₂ . In the presence of other aluminum compounds (e.g.

,

,

, EtAlCl ₂ , Et ₂ AlCl), other unsaturated compounds (α-olefins, dienes, acetylenes) 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 more than 6 mol% with respect to methylene cyclobutane does not significantly increase the yield of the target product (1). The use of the catalyst Cp ₂ ZrCl ₂ less than 4 mol% reduces the yield of 6-thiaspiro [3,4] octane (1), which is possibly associated with a decrease in catalytically active centers in the reaction mass.

The process (after adding SOCl ₂ ) at a higher temperature (for example, 0 ° C) reduces the selectivity of the reaction. Carrying out the process at a lower temperature (for example, -50 ° C) reduces the reaction rate. A change in the ratio of the starting reagents in the direction of increasing their content relative to the starting methylene cyclobutane does not lead to a significant increase in the yield of the target product (1).

Reactions were carried out using aliphatic solvents (hexane). In other solvents (e.g., ether), the reaction does not proceed.

Significant differences of the proposed method:

In the known method, the thiolane of the spiran series (4) is obtained by intramolecular cyclization of homoallyl mercaptan (3) under the action of the Pr ₃ BO ₂ —CH ₃ OH system. In the proposed method, 6-thiaspiro [3,4] octane (1) is obtained from methylene cyclobutane and Et ₃ Al with the participation of Cp ₂ ZrCl ₂ as a catalyst, followed by treatment of the reaction mixture with SOCl ₂ .

The proposed method has the following advantages:

1. The method allows to obtain with high selectivity 6-thiaspiro [3,4] octane of the general formula (1).

The method is illustrated by the following examples:

EXAMPLE 1. In a 50 ml glass reactor mounted on a magnetic stirrer, 2 ml of hexane, 10 mmol of methylenecyclobutane, 0.5 mmol of catalyst Cp ₂ ZrCl ₂ are placed in an argon atmosphere, at a temperature of ~ 0 ° C, 12 mmol of AlEt ₃ are stirred for 4 hours at room temperature (20-21 ° C), then the reaction mixture was cooled to -40 ° C, is added 12 mmol of thionyl chloride (SOCl ₂₎ and stirred at this temperature for 7 hours. At the end of the reaction, the reaction mass is treated with 5% HCl, 6-thiaspiro [3,4] octane (1) is isolated in 64% yield.

Spectral characteristics of 6-thiaspiro [3,4] octane (1):

¹³ C NMR spectrum (δ, ppm) of 6-thiaspiro [3,4] octane (1): 15.29, 30.60, 32.75, 40.95, 42.19, 42.64.

Other examples confirming the method are given in table 1.

№№p / p The molar ratio of methylene cyclobutane: AlEt ₃ : Cp ₂ ZrCl ₂ : SOCl ₂ , mmol Total reaction time, h The yield of 6-thiaspiro [3,4] octane (1),% one 2 3 four one 10: 12: 0.5: 12 eleven 64 2 10: 14: 0.5: 14 eleven 68 3 10: 10: 0.5: 10 eleven 56 four 10: 12: 0.6: 12 eleven 74 5 10: 12: 0.4: 12 eleven 53 6 10: 12: 0.5: 12 12 66 7 10: 12: 0.5: 12 10 59

The experiments were carried out in hexane at room temperature (20-21 ° C). The addition of thionyl chloride and the subsequent sulfonation reaction were carried out at a temperature of -40 ° C.

Claims (1)

The method of obtaining 6-thiaspiro [3,4] octane of the General formula (1)

,
characterized in that methylenecyclobutane is reacted with triethylaluminum (AlEt ₃ ) in the presence of a catalyst of zirconacene dichloride (Cp ₂ ZrCl ₂ ) at a molar ratio of methylene cyclobutane: AlEt ₃ : Cp ₂ ZrCl ₂ = 10: 10-14: 0.4-0.6 in atmosphere of argon at room temperature and atmospheric pressure in hexane for 4 hours, followed by the addition of thionyl chloride (SOCl ₂ ), taken in an amount equimolar to AlEt ₃ , to the reaction mass at -40 ° C and stirring at this temperature for 6 -8 hours