RU2250892C2 - Method for production of 1,3,4-trialkylcyclopentane-1-ols - Google Patents

Abstract

FIELD: organic chemistry, organic synthesis, paint-vehicle production.

SUBSTANCE: invention relates to new method for production of 1,3,4-trialkylcyclopentane-1-ols of general formula 1

, wherein R is n-C₄H₉, n-C₆H₁₃, R' is CH₃, C₂H₅, useful in production of paint-vehicle production, high effective antiscoring and antiwear additives for oils, bioactive compounds, etc. Claimed method includes interaction of alpha-olefins of general formula RCH=CH₂, wherein R is as described above, with ethylaluminum dichloride EtAlCl₂ and magnesium in ratio RCH=CH₂:EtAlCl₂:Mg of 10:(5-7):(5-7) in presence of zirconacene dichloride Cp₂ZrCl₂ as catalyst in molar ratio Cp₂ZrCl₂/alpha-olefin of 0.03-0.07; in argon atmosphere, at room temperature and ambient pressure in tetrahydrofuran medium, followed by addition into reaction mass nickel chloride phosphine complex [NiCl₂.2Ph₃P] in molar ratio [NiCl₂.2Ph₃P]/alpha-olefin of 0.08-0.12, and carboxylic acid ethyl ester R'CO₂Et in triple molar excess expressed as EtAlCl₂. Target product yield after hydrolysis of reaction mass is 50-74 %.

EFFECT: method of increased yield; products for organic synthesis of improved quality.

1 tbl, 1 ex

Description

The present invention relates to organic chemistry, in particular to a method for producing 1,3,4-trialkylcyclopentan-1-ol of the general formula (I):

, где R=н-С₄Н₉, н-С₆Н₁₃, н-C₈H₁₇; R¹=СН₃, С₂Н₅

where R = n — C ₄ H ₉ , n — C ₆ H ₁₃ , n — C ₈ H ₁₇ ; R ¹ = CH ₃ , C ₂ H ₅

Cycloalkanols and their derivatives can be used in fine organic synthesis, in the production of paints and varnishes, highly effective anti-seize and anti-wear additives for oils, biologically active substances.

A known method ([1] Nenitzescu CD, Necsoin I. The Synthesis of Cyclic Alcohols and Olefms by the Interaction of Dimagnesium Halides and Esters // J. Amer. Chem. Soc., 1950, 72, 3483-3486) for producing cycloalkanols, for example , 1-methylcyclohexan-1-ol (2) by the interaction of 1,5-dimagnesium pentane with an equimolar amount of ethyl acetate according to the scheme:

The known method does not allow to obtain 1,3,4-trialkylcyclopentan-1-ol of the General formula (1).

The known method ([2]. Swanson DR, Rousset CJ, E.-I. Negishi, Takahashi T., Seki T., Saburi M., Uskida J. Regioselective and Diastereoselective Alkyl-Alkene and Alkene-Alkene Coupling Promoted by Zirconocene and Hafnocene // J. Org. Chem. 1989, V.54, No. 15, P.3521-3523) for the preparation of trans-3,4-dialkylcyclopentan-1-ol by the reaction of zirconacenedichloride (Cp ₂ ZrCl ₂ ) with a twofold excess of alkyl lithium derivatives followed by sequential treatment of the reaction mass with α-olefins, carbon monoxide (CO) and water according to the scheme:

R = Et, n-Hex

In a known manner, 1,3,4-trialkylcyclopentan-1-oles (1) cannot be obtained.

A new method is proposed for the synthesis of 1,3,4-trialkylcyclopentan-1-ol (1).

The essence of the method consists in the interaction of α-olefins of the general formula RCH = CH ₂ , where R = n-C ₄ H ₉ , n-C ₆ H ₁₃ , n-C ₈ H ₁₇ , with ethyl aluminum dichloride (EtAlCl ₂ ) and magnesium (Mg, powder), taken in a molar ratio of RCH = CH ₂ : EtAlCl ₂ : Mg = 10: (5-7) :( 5-7), in the presence of a catalyst of zirconacide dichloride Cp ₂ ZrCl ₂ , taken in a molar ratio of Cp ₂ ZrCl ₂ to α α-olefin, equal to 0.3-0.7, in an argon atmosphere at room temperature (20-21 ° C) and atmospheric pressure in tetrahydrofuran (THF), followed by the addition of nickel chloride phosphine complex [NiCl ₂ · 2Ph ₃ to the reaction mass of the catalyst P] when the molar ratio of [NiCl ₂ · 2Ph ₃ P] to the α-olefin, equal to 0.8-1.2, and ethyl carboxylic acid ester (R ¹ CO ₂ Et, where R ¹ = CH ₃ , C ₂ H ₅ ) in triplicate molar excess with respect to EtAlCl ₂ , followed by stirring of the reaction mixture at room temperature (20-21 ° C) for 6-8 hours. The total yield of 1,3,4-trialkylcyclopentan-1-ol (1) after hydrolysis of the reaction mass is 50-74%. The reaction proceeds according to the scheme:

R = n-C ₄ H ₉ , n-C ₆ H ₁₃ , n-C ₈ H ₁₇ ; R = CH ₃ , C ₂ H ₅

1,3,4-trialkylcyclopentan-1-oles (1) are formed only with the participation of EtAlCl ₂ , Mg, α-olefins, ethyl esters of carboxylic acids and catalysts Cp ₂ ZrCl ₂ , [NiCl ₂ · 2Ph ₃ P]. In the presence of other aluminum compounds (e.g. Bu $\genfrac{}{}{0ex}{}{\text{i}}{\text{2}}$ AlCl, Bu $\genfrac{}{}{0ex}{}{\text{i}}{\text{3}}$ Al Bu $\genfrac{}{}{0ex}{}{\text{i}}{\text{2}}$ AlH, Et ₃ Al, Et ₂ AlCl) or other catalysts (for example, Zr (acac) ₄ , FeCl ₃ , Cp ₂ TiCl ₂ , TiCl ₄ , CoCl ₂ , Fe (acac) ₃ ) the target products (1) are not formed.

Reactions were carried out using ether solvents (THF). In other solvents (for example, aliphatic, aromatic), the reaction does not proceed.

Significant differences of the proposed method.

In the proposed method, EtAlCl ₂ , magnesium, esters (ethyl esters of carboxylic acids) and catalysts Cp ₂ ZrCl ₂ , [NiCl ₂ · 2Ph ₃ P] are used as starting compounds. In the known method, alkyl lithium derivatives, gaseous CO, and Cp ₂ ZrCl ₂ in stoichiometric amounts are used as starting reagents.

The proposed method allows to obtain 1,3,4-trialkylcyclopentan-1-ol (1) based on the available starting reagents under mild conditions (20-21 ° C).

The method is illustrated by the following examples:

EXAMPLE 1. In a 50 ml glass reactor mounted on a magnetic stirrer, 10 ml of THF, 10 mmol of 1-hexene, 0.5 mmol of catalyst Cp ₂ ZrCl ₂ , 6 mmol of Mg (powder) at a temperature of ~ 0 ° C are placed in an argon atmosphere 6 mmol EtAlCl ₂ , stirred for 8 hours at room temperature 20-21 ° C, then at a temperature of -15 ° C add 1 mmol of catalyst [NiCl ₂ · 2Ph ₃ P] and 18 mmol of ethyl acetate, stirred for 7 hours at a temperature of 20-21 ° C, the reaction mass is hydrolyzed with an aqueous solution (5-7%) of Hcl. 1-methyl-3,4-di (n-butyl) cyclopentan-1-ol is isolated from the organic layer in 64% yield.

Spectral characteristics of 1-methyl-3,4-di (n-butyl) cyclopentan-1-ol (1):

ИК-спектр (ν , см^-1): 3345, 2945, 2990, 2850, 1730, 1445, 1385, 1230, 1030, 930, 725. Спектр ЯМР ¹Н (δ , м.д.): 0.84-0.96 (м, 9Н, СН₃), 1.28 (м, 12Н, СН₂), 2.02-2.54 (м, 6Н, СН, СН₂ в цикле), 3.51-3.64 (м, СН-ОН). Спектр ЯМР ¹³С (δ , м.д.): 72.24 (С¹), 42.52 (С²), 37.36 (С³), 26.62 (С⁴), 31.98 (С⁵), 22.44 (С⁶), 14.08 (С⁷), 26.29 (С⁸). Масс-спектр, m/z: 194[М-18]⁺.

IR spectrum (ν, cm ^-1 ): 3345, 2945, 2990, 2850, 1730, 1445, 1385, 1230, 1030, 930, 725. ¹ H NMR spectrum (δ, ppm): 0.84-0.96 ( m, 9H, CH ₃ ), 1.28 (m, 12H, CH ₂ ), 2.02-2.54 (m, 6H, CH, CH ₂ in the cycle), 3.51-3.64 (m, CH-OH). ¹³ C NMR spectrum (δ, ppm): 72.24 (C ¹ ), 42.52 (C ² ), 37.36 (C ³ ), 26.62 (C ⁴ ), 31.98 (C ⁵ ), 22.44 (C ⁶ ), 14.08 (C ⁷ ), 26.29 (C ⁸ ). Mass spectrum, m / z: 194 [M-18] ⁺ .

Other examples confirming the method are given in table 1.

Table 1 №№

Starting α-olefin,

Starting ester, R ¹ CO ₂ Et Molar ratio

: EtAlCl ₂ : Mg: Cp ₂ ZrCl ₂ : R ¹ CO ₂ Et: [NiCl ₂ · 2Ph ₃ P] Yield (1),% 1 2 3 4 6 1.

1-hexene CH ₃ CO ₂ Et ethyl acetate 10: 6: 6: 0.5: 18: 1 64 2. - - 10: 7: 6: 0.5: 21: 1 68 3. - - 10: 5: 6: 0.5: 15: 1 58 4. - - 10: 6: 7: 0.5: 18: 1 65 5. - - 10: 6: 5: 0.5: 18: 1 61 6. - - 10: 6: 6: 0.7: 18: 1 72 7. - - 10: 6: 6: 0.3: 18: 1 54 8. - - 10: 6: 6: 0.5: 18: 1.2 74 9. - - 10: 6: 6: 0.5: 18: 0.8 fifty 10. - - 10: 6: 6: 0.5: 18: 1 66 eleven. - - 10: 6: 6: 0.5: 18: 1 56 12.

1 octene - 10: 6: 6: 0.5: 18: 1 62 thirteen.

1 decen - 10: 6: 6: 0.5: 18: 1 57 14. - C ₂ H ₅ CO ₂ Et ethyl propionate 10: 6: 6: 0.5: 18: 1 51

The experiments were carried out in THF at room temperature (20-21 ° C).

Claims (1)

The method of obtaining 1,3,4 - trialkylcyclopentan-1-ol of the General formula (1)

(1) where R = n — C ₄ H ₉ , n — C ₆ H ₁₃ , n — C ₈ H ₁₇ , R ^′ = CH ₃ , C ₂ H ₅ , characterized in that α-olefins of the general formula RCH = CH ₂ , where R is the same as defined above, are reacted with ethyl aluminum EtAlCl ₂ and magnesium with a ratio of RCH = CH ₂ : EtAlCl ₂ : Mg equal to 10: (5-7 ) :( 5-7), in the presence of a catalyst for zirconacene dichloride Cr ₂ ZrCl ₂ , taken at a molar ratio _of Cr ₂ ZrCl ₂ to α-olefin equal to 0.03-0.07, in an argon atmosphere at room temperature and atmospheric pressure in the medium tetrahydrofuran, followed by the addition of nickel chloride phosphine complex [NiCl ₂ · 2Ph ₃ P] to the reaction mass of the catalyst with a molar the ratio of [NiCl ₂ · 2Ph ₃ P] to the α-olefin equal to 0.08-0.12, and the carboxylic acid ethyl ester R'CO ₂ Et in a three-fold molar excess with respect to EtAlCl _2.