CN1680038A - Ionic liquid of 1,3-diester-base imidazole and preparation thereof - Google Patents

Abstract

A 1,3-dialiphatic imidazole ion liquid is prepared through reaction between imidazole and double bond contained unsaturated ester to obtain 1-aliphatic imidazole, protonating by HCl, hexafluorophosphoric acid, or tetrafluoroboric acid, and reaction on double bond contained unsaturated ester to obtain the 1,3-dialiphatic imidazole ion liquid.

Description

1,3-diester-base imidazole ionic liquid and preparation method thereof

Technical field

The present invention relates to the ionic liquid technical field, specifically be meant a kind of 1,3-two ester group substituted imidazole type ionic liquids and preparation method thereof.

Background technology

In recent years, as a class green solvent and a catalyst, ionic liquid obtains the extensive concern of domestic and international research institution and enterprise, and ionic liquid is widely used in having functions such as solvent, catalyst in reactions such as organic synthesis, electrochemistry, Chemical Decomposition and petrochemical industry and the process.Because that ionic liquid has is non-volatile, do not have vapour pressure, liquid temperature regional extent extensively, etc. characteristics, with using traditional organic technology to compare, use ion liquid system to be considered to eco-friendly technical process.P.Wasserscheid and T.Welton mentioned in its being entitled as in the 7th～8 page of Ionic Liquids in Synthesis one book of writing, the compounds that ionic liquid is made up of zwitterion, present ion liquid cation mainly contains quaternary ammonium alkyl ion, alkyl quaternary phosphine ion, alkyl substituted imidazole ion and alkyl substituted pyridines ion four classes, and anion mainly contains Cl ^-, Br ^-, CH ₃COO ^-, HSO ₄ ^-, CF ₃COO ^-, BF ₄ ^-, PF ₆ ^-Or NO ₃ ^-Deng, by the various combination of zwitterion, mix ionic liquid with different physics, chemical property.How ring synthetic L-sulforamidate type chiral ionic liquid (Chinese invention patents such as unit, publication number CN1383920A), synthetic diacetone acrylic amide type ionic liquid (Chinese invention patent such as He Mingyuan, publication number CN1385243A), the synthetic ionic liquid that contains unsaturated double-bond (Chinese invention patent such as Zhang Jun, publication number CN1417407A), synthetic hexaalkylguanidium salts ionic liquid (Chinese invention patent, publication number CN1491939A) such as Zhang Suobo etc.The synthetic ion liquid method that has ester group of Britain Green Chemistry magazine 2004 the 6th phases the 166th～175 page of report is that employing 1-methylimidazole and halogen ester are raw material, the direct synthetic 1-ester group of reaction-3-methylimidazole ionic liquid, aspect such as substituting group number all exists different greatly with the present invention on method reaction raw materials, reaction scheme and the imidazole ring of this report; The ion liquid method that the preparation of Britain Chem.Commun. magazine the 2038th～2039 page of report in 2003 contains ester group is under the pyridine catalytic action, methylimidazole and tetrafluoro boric acid is reacted, and then react with butyl acrylate, obtains ion liquid compound.Similarly, this method aspect such as substituting group number on reaction raw materials, reaction scheme and imidazole ring all exists different greatly with the present invention; Simultaneously, involved in the present invention contain 1,3-two ester group substituted imidazole type ionic liquids do not appear in the newspapers so far, its preparation method also is that the present invention mentions first.The present invention relates to 1, ion liquid preparation technology is simple for 3-two ester group substituted imidazole types, by the method that the present invention relates to, it is novel 1 to prepare series, 3-two ester group substituted imidazole type ion liquid compounds.

Summary of the invention

Purpose of the present invention is exactly in order to solve above-mentioned the deficiencies in the prior art part, provides a kind of 1,3-two ester group substituted imidazole type ionic liquids and preparation method thereof.

The object of the invention is achieved through the following technical solutions:

Described a kind of 1,3-two ester group substituted imidazole type ionic liquids, its chemical structure of general formula is as follows:

Wherein, R ₁, R ₂Be monoesters base with following structure:

-C _nH _2nCOOC _mH _2m+1，

Wherein, m and n are natural number, n=1～10, m=1～10;

Or the dibasic acid esters base of following structure:

Wherein, m, n, x and y are natural number, m=1～10; X=1～8, x+y＜10; X ^-Be Cl ^-, Br ^-, BF ₄ ^-, PF ₆ ^-, CH ₃COO ^-, CF ₃COO ^-, CF ₃SO ₃ ^-Or NO ₃ ^-

Described a kind of 1,3-two ester group substituted imidazole type preparation method of ionic liquid comprise the steps and process conditions:

(1) makees solvent with acetone or toluene, with imidazoles and the mixed in molar ratio of the beta-unsaturated esters that contains two keys, backflow and reaction 12-16 hour by 1: 1～1: 1.5; Steam solvent and unreacted raw material then, obtain 1-ester group imidazoles;

(2) at normal temperatures, utilize HCl, hexafluorophosphoric acid or tetrafluoro boric acid as protonating agent, 1-ester group imidazoles is protonated, and wherein the mol ratio of protonating agent and 1-ester group imidazoles is 1: 1～2: 1,

(3) with alcohol be solvent, the protonated 1-ester group imidazole salts that step (2) is obtained is mixed with the beta-unsaturated esters that contains two keys and is stirred, and after reacting completely, reduces pressure and steams solvent, obtains 1,3-two ester group substituted imidazole type ionic liquids; Wherein, protonated 1-ester group imidazole salts is 1: 1～1: 1.5 with the mol ratio of the beta-unsaturated esters that contains two keys.

In addition, with 1,3-two ester group substituted imidazole ionic liquids with contain and BF ₄ ^-, PF ₆ ^-, CH ₃COO ^-, CF ₃COO ^-, CF ₃SO ₃ ^-Or NO ₃ ^-After anionic sylvite or sodium salt mix, the powerful stirring, after reacting completely, repeatedly through halogen freezing, that remove by filter generation, decompression distillation removes and desolvates, and can obtain series 1,3-two ester group substituted imidazole type ionic liquids.

The present invention compared with prior art has following advantage and beneficial effect:

1, the present invention is to provide serial novel ion liquid, developed the ionic liquid new varieties;

2,, can prepare series 1,3-two ester group substituted imidazole type ionic liquids by method provided by the invention;

3, of the present invention preparation is simple, and suitable large-scale industrial production.

Description of drawings

Fig. 1 is an ion liquid chemical structural formula of the present invention.

The specific embodiment

Embodiment 1:1,3-(ethyl 3--propanoate base) imidazolium chloride is ion liquid synthetic

Get the 1mol imidazoles and be dissolved in 200ml toluene, add the 1.1mol ethyl acrylate, refluxed 24 hours, the pressure reducing and steaming solvent obtains 1-(ethyl 3--propanoate base) imidazoles, then at normal temperatures, watery hydrochloric acid and 1-(ethyl 3--propanoate base) will be mixed in the ratio of 1.5: 1 (mol ratio of HCl and 1-(ethyl 3--propanoate base) imidazoles in the watery hydrochloric acid), stir 5h, decompression distillation, remove unreacted hydrochloric acid and moisture content, add an amount of absolute ethyl alcohol and ethyl acrylate (mol ratio of the ethyl acrylate of adding and 1-(ethyl 3--propanoate base) imidazoles is 1.2: 1), stir and also react 12h, pressure reducing and steaming ethanol at normal temperatures, just obtain 1,3-(ethyl 3--propanoate base) imidazolium chloride ionic liquid, productive rate is 95%, reaction equation is:

Embodiment 2:1,3-(3-butyl propionate base) imidazolium bromide is ion liquid synthetic

Get the 1mol imidazoles and be dissolved in 200ml acetone, add the 1.1mol butyl acrylate, refluxed 24 hours, the pressure reducing and steaming solvent obtains 1-(3-butyl propionate base) imidazoles, then at normal temperatures, the HBr aqueous solution and 1-(3-butyl propionate base) imidazoles are mixed in the ratio of 1.5: 1 (mol ratio of HBr and 1-(3-butyl propionate base) imidazoles in the HBr aqueous solution), stir 10h, decompression distillation, remove HBr and moisture content, add an amount of anhydrous normal butyl alcohol 1-butyl acrylate (mol ratio of the butyl acrylate of adding and 1-(3-butyl propionate base) imidazoles is 1.3: 1), stirring is also reacted 12h, pressure reducing and steaming ethanol under 50 ℃, just obtain 1,3-(3-butyl propionate base) imidazolium bromide ionic liquid, productive rate is 96%, reaction equation is:

Embodiment 3:1,3-(5-valeric acid monooctyl ester base) imidazoles hexafluorophosphate is ion liquid synthetic

Get the 1mol imidazoles and be dissolved in 200ml acetone, add 1.1mol 4-penetenoic acid monooctyl ester, refluxed 24 hours, the pressure reducing and steaming solvent obtains 1-(5-valeric acid monooctyl ester base) imidazoles, then at normal temperatures, the hexafluorophosphoric acid aqueous solution and 1-(5-valeric acid monooctyl ester base) imidazoles are mixed in the ratio of 1: 1 (mol ratio of hexafluorophosphoric acid and 1-(5-valeric acid monooctyl ester base) imidazoles in the hexafluorophosphoric acid aqueous solution), stir 6h, decompression distillation, remove moisture content, add an amount of anhydrous n-octyl alcohol and 4-penetenoic acid monooctyl ester (mol ratio of the 4-penetenoic acid monooctyl ester of adding and 1-(5-valeric acid monooctyl ester base) imidazoles is 1.1: 1), stirring is also reacted 20h, pressure reducing and steaming n-octyl alcohol under 60 ℃, just obtain 1,3-(5-valeric acid monooctyl ester base) imidazoles hexafluorophosphoric acid ionic liquid, productive rate is 90%, reaction equation is:

Embodiment 4:1,3-(two-the ethyl 3--propanoate base) tetrafluoroborate is ion liquid synthetic

Get among the embodiment 11 of preparation, 0.1 mole of 3-(ethyl 3--propanoate base) imidazolium chloride and with the aqueous solution that contains 0.1 mole of sodium tetrafluoroborate, stir 5h, add carrene, filter, steam carrene after the drying organic facies, just obtain 1,3-(ethyl 3--propanoate base) tetrafluoroborate, productive rate is 92%, reaction equation is:

Embodiment 5:1,3-(two-2-methyl butyrate base) imidazolium chloride is ion liquid synthetic

Get the 1mol imidazoles and be dissolved in 200ml acetone, add the 1.1mol dimethyl maleate, refluxed 24 hours, the pressure reducing and steaming solvent obtains 1-(two-2-methyl butyrate base) imidazoles, then at normal temperatures, watery hydrochloric acid and 1-(two-2-methyl butyrate base) imidazoles are mixed in the ratio of 1.5: 1 (mol ratio of HCl and 1-(two-2-methyl butyrate base) imidazoles in the watery hydrochloric acid), stir 5h, decompression distillation, remove unreacted hydrochloric acid and moisture content, add an amount of absolute methanol and dimethyl maleate (mol ratio of the dimethyl maleate of adding and 1-(two-2-methyl butyrate base) imidazoles is 1: 1), stirring is also reacted 12h, pressure reducing and steaming methyl alcohol under 70 ℃, just obtain 1,3-(two-2-methyl butyrate base) imidazolium chloride ionic liquid, productive rate is 88%, reaction equation is:

Embodiment 6:1-(two-2-ethyl butyrate base)-3-(ethyl 3--propanoate base) imidazolium chloride is ion liquid synthetic

Getting 0.1 mole of 1-among the embodiment 1 (ethyl 3--propanoate base) imidazoles mixes with the watery hydrochloric acid that contains 0.15molHCl, stir 5h, decompression distillation, remove unreacted hydrochloric acid and moisture content, add an amount of absolute ethyl alcohol and 0.1mol dimethyl maleate then, stirring is also reacted 8h under 50 temperature, pressure reducing and steaming ethanol, just obtain 1-(two-2-ethyl butyrate base)-3-(ethyl 3--propanoate base) imidazolium chloride ionic liquid, productive rate is 86%, and reaction equation is:

Embodiment 7:1,3-(ethyl 3--propanoate base) imidazoles fluoroform sulphonate is ion liquid synthetic

Get among the embodiment 11 of preparation, 0.1 mole of 3-(ethyl 3--propanoate base) imidazolium chloride is also mixed with 0.1 mole of TFMS sodium and an amount of carrene, stir 5h, after filtration, steam carrene after the freezing and dry organic facies, just obtain 1,3-(ethyl 3--propanoate base) imidazoles fluoroform sulphonate, productive rate is 95%.

Embodiment 8:1,3-(ethyl 3--propanoate base) imidazoles acetate ionic liquid synthetic

Get among the embodiment 11 of preparation, 0.1 mole of 3-(ethyl 3--propanoate base) imidazolium chloride is also mixed with 0.1 molar acetate potassium and an amount of carrene mixes, stir 5h, after filtration, steam carrene after the freezing and dry organic facies, just obtain 1,3-(ethyl 3--propanoate base) imidazoles acetate, productive rate is 95%.

Embodiment 9:1,3-(two-2-methyl butyrate base) imidazole nitrate is ion liquid synthetic

Get among the embodiment 51 of preparation, 3-(two-2-methyl butyrate base) 0.1 mole of chloride ion liquid and with contain 0.1 molar nitric acid sodium and an amount of carrene and mix, stir 11h, after filtration, steam carrene after the freezing and dry organic facies, just obtain 1,3-(two-2-methyl butyrate base) azoles miaow nitrate ion liquid, productive rate is 92%.

Claims (5)

1,1,3-two ester group substituted imidazole type ionic liquids is characterized in that having following chemical structure of general formula:

2, described 1 according to claim 1,3-two ester group substituted imidazole type ionic liquids is characterized in that described R ₁, R ₂For having the monoesters base of following structure:

-C _nH _2nCOOC _mH _2m+1Wherein, m and n are natural number, m=1～10, n=1～1 0.

3, described 1 according to claim 1,3-two ester group substituted imidazole type ionic liquids is characterized in that described R ₁, R ₂For having the dibasic acid esters base of following structure:

Wherein, m, n, x and y are natural number, m=1～10; X=1～8, x+y＜10.

4, according to claim 1 or 2 or 3 described 1,3-two ester group substituted imidazole type ionic liquids is characterized in that, wherein X ^-Be Cl ^-, Br ^-, BF ₄ ^-, PF ₆ ^-, CH ₃COO ^-, CF ₃COO ^-, CF ₃SO ₃ ^-Or NO ₃ ^-

5, claim 1 is described 1, and 3-two ester group substituted imidazole type preparation method of ionic liquid is characterized in that, comprise the steps and process conditions:

(1) makees solvent with acetone or toluene,, reflux and reacted 12～16 hours, steam solvent and unreacted raw material then, obtain 1-ester group imidazoles imidazoles and the mixed in molar ratio of the beta-unsaturated esters that contains two keys by 1: 1～1: 1.5;

(2) at normal temperatures, utilize HCl, hexafluorophosphoric acid or tetrafluoro boric acid as protonating agent, 1-ester group imidazoles is protonated, and wherein the mol ratio of protonating agent and 1-ester group imidazoles is 1: 1～2: 1;

(3) with alcohol be solvent, the protonated 1-ester group imidazole salts that step (2) is obtained is mixed with the beta-unsaturated esters that contains two keys and is stirred, and after reacting completely, reduces pressure and steams solvent, obtains 1,3-two ester group substituted imidazole type ionic liquids; Wherein, protonated 1-ester group imidazole salts is 1: 1～1: 1.5 with the mol ratio of the beta-unsaturated esters that contains two keys.