CN103145553B

CN103145553B - The Synthesis and application of 2,3-Hydrocarbyl-substituted succinic acid diesters

Info

Publication number: CN103145553B
Application number: CN201310071720.2A
Authority: CN
Inventors: 高占先; 陈秋菊; 韩如冰; 于丽梅
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2013-03-06
Filing date: 2013-03-06
Publication date: 2016-06-01
Anticipated expiration: 2033-03-06
Also published as: CN103145553A

Abstract

The present invention relates to the Synthesis and application of 2,3-Hydrocarbyl-substituted succinic acid diesters. At low temperatures, carboxylicesters and highly basic LDA react and form enolate, and tetracol phenixin oxidative coupling prepares 2,3-dialkyl succinic acid diester. Adopting liquid nitrogen to lead to the novel method directly freezed into reaction system, liquid nitrogen has shielding gas and refrigeration two kinds of functions. Direct method of cooling has temperature of reaction energy-conservation, easy to control, substitutes the advantage of inert protective gas. 2,3-Hydrocarbyl-substituted succinic acid diesters can be used as the electron donor of polypropylene catalyst.

Description

Synthesis and application of 2, 3-alkyl substituted diester succinate

Technical Field

The invention belongs to the field of organic synthesis research, relates to a synthesis method of an organic compound, and particularly relates to synthesis of 2, 3-alkyl substituted succinic diester and application of the 2, 3-alkyl substituted succinic diester synthesized by the method in preparation of a polypropylene catalyst.

Background

The Ziegler-Natta catalyst is the mainstream catalyst of industrial polypropylene catalysts and is widely applied. Generally, an organic base is added as an internal electron donor during the preparation of the ziegler-natta catalyst; alkali is added in the propylene polymerization process as an external electron donor. The electron donor can obviously improve the performance of the catalyst, such as improving the activity of the catalyst, improving the isotacticity of polypropylene, improving the bulk density of the polymer, improving the relative molecular mass and the relative molecular mass distribution of the polymer and the like. The search for ideal internal electron donor compounds has been a hotspot in the research of ziegler-natta catalysts. The prior patent CN00801123 and other patents disclose that succinate compounds are used as electron donors of catalysts, and have the following advantages when applied to propylene polymerization reaction. 1) The catalyst has low cost, 2) the catalyst has high activity and polypropylene isotacticity, 3) the polypropylene has wide molecular weight distribution, 4) the catalyst can be used as an internal electron donor and also can be used as an external electron donor, 5) the catalyst can be used independently when being used as an internal electron donor, and can be used together with other internal electron donors to change the performance of the catalyst, and 6) the polypropylene product has high impact resistance and flexural modulus.

In the literature, the method for synthesizing 2, 3-hydrocarbyl-substituted succinic acid diester includes esterification, electrolysis, condensation, oxidative coupling and the like, in the article of actachem, Scand.13(1959)40-49, Eberson L prepares 2, 3-hydrocarbyl-substituted succinic acid diester by an electrolysis method, the electrolysis conditions selected by the method are harsh, the yield of the target product is low, only limited to laboratory studies and difficult to form industrial production, U.S. Pat. No. 3A1 discloses a synthetic method, under the action of strong base, succinic acid diester and ketone or aldehyde condensation react to obtain 2, 3-dialkenyl succinic acid diester, the reaction route has many reaction steps, the yield is low and the post-treatment is complicated, in the article of Russian chemical Bulletin, International edition,58 (1672009) 2 decarboxylation 0, A.L. Lyubimsev adopts isovaleric acid as a raw material, after LDA treatment, the hydrocarbon-substituted succinic acid diester is generated by oxidative coupling, the reaction is taken as a dialkyl succinate, after the hydrocarbon-substituted succinic acid diester is generated by the oxidation reaction route 1682, the oxidation reaction is taken as a raw material, the reaction route 2, the oxidation reaction route is taken as a long route, the raw material, the oxidation reaction route 2, the oxidation reaction route is taken, the oxidation reaction route 2-bis-alkyl succinic acid diester is taken as a, the raw material after the oxidation reaction route 2-2 substitution reaction is obtained by the oxidation reaction route 2-2 substitution reaction, the oxidation reaction is taken, the oxidation reaction route 2-2 substitution reaction, the oxidation reaction route is taken as the raw material, the oxidation reaction route 2 substitution reaction route is taken, the raw material, the oxidation reaction route is taken as the raw material is taken, the oxidation reaction route 2 substitution reaction route is taken as the reaction route 2-2 substitution reaction route is₄Oxidative coupling gives 2, 3-dihydrocarbylsuccinic diesters. CN1313869A outlines various synthetic methods that can be used for 2, 3-dihydrocarbylsuccinic acid diesters. Wherein 2-alkyl acetate is used as raw material, TiCl is selected₄The route of the coupling agent is simple, and the coupling agent is suitable for preparing 2, 3-alkyl substituted succinic acid diester. However, the reaction requires a temperature of-78 deg.C, and the reaction system is cooled by a slurry mixture of liquid nitrogen and organic substances such as ethanol or acetone as an indirect coolant, which has disadvantages that the reaction temperature is not easily adjusted,energy is wasted, and industrial production is not easy to realize. The invention innovatively adopts liquid nitrogen to be introduced into the reactor to directly cool reactants, and solves the refrigeration problem so as to realize industrial production.

Disclosure of Invention

The invention aims to provide a synthesis method for directly cooling a reaction system of a 2, 3-alkyl substituted succinic diester compound, and solves the problem that industrial production is difficult due to the fact that low-temperature conditions in the synthesis process are not easy to control.

In order to achieve the purpose, the invention adopts the following technical scheme:

a synthetic method for preparing 2, 3-alkyl substituted succinic diester compound with a structure of a general formula I comprises the steps of reacting carboxylic ester with strong base in a solvent to form enol metal salt, and then oxidizing and coupling the enol metal salt with an oxidizing agent, and also comprises the steps of introducing liquid nitrogen into a reactor to directly cool reaction liquid, and enabling the reaction temperature to be-100-25 ℃; in the reaction process, liquid nitrogen can be used as inert protective gas after gasification. The carboxylic ester used in the method is at least 1 of carboxylic esters with a structural general formula II;

wherein,

R₁、R₂each independently selected from H or C₁～C₂₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl; the 2, 3-hydrocarbyl-substituted succinic acid diesters thus synthesized are 2, 3-unsubstituted succinic acid diesters, 2, 3-monohydrocarbyl-substituted succinic acid diesters, 2, 3-dihydrocarbyl-substituted succinic acid diesters, 2, 3-trihydrocarbyl-substituted succinic acid diesters and 2, 3-tetraalkyl-substituted succinic acid diesters.

R₃Is selected from C₁～C₂₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl.

When carboxylic ester is cross-coupled with different ester, two R in synthesized 2, 3-alkyl substituted succinic diester structure₁Two R₂Two R₃Each being the same or different, R₁And R₂And may be the same or different.

In the method provided by the invention, in a preferred scheme, R is₁、R₂Each independently selected from H or C₁～C₁₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl; r₃Is selected from C₁～C₁₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl. From the ecological environmental point of view, R₁、R₂、R₃When it is a hydrocarbon group, C₁～C₁₀The hydrocarbon group (b) is preferably a linear hydrocarbon group, a branched hydrocarbon group, a cyclic hydrocarbon group, a chain hydrocarbon-based cyclic hydrocarbon group, or a cyclic hydrocarbon-based chain hydrocarbon group.

Further, the carboxylic acid ester having the general structural formula II is selected from ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, 2-ethylhexyl acetate, ethyl propionate, propyl propionate, isopropyl propionate, butyl propionate, isobutyl propionate, 2-ethylhexyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, amyl butyrate, isoamyl butyrate, 2-ethylhexyl butyrate, ethyl isobutyrate, propyl isobutyrate, isopropyl isobutyrate, butyl isobutyrate, isobutyl isobutyrate, 2-ethylhexyl isobutyrate, ethyl valerate, propyl valerate, isopropyl valerate, butyl valerate, isobutyl valerate, isoamyl valerate, ethyl isovalerate, propyl isovalerate, isopropyl isovalerate, butyl isovalerate, isobutyl isovalerate, isopropyl isovalerate, butyl isovalerate, isopropyl isovalerate, isobutyl isovalerate, ethyl isovalerate, isopropyl isovalerate, butyl isovalerate, isopropyl, Isoamyl isovalerate, ethyl hexanoate, propyl hexanoate, isopropyl hexanoate, butyl hexanoate, isobutyl hexanoate, 2-ethylhexyl hexanoate, ethyl isohexanoate, isopropyl isohexanoate, butyl isohexanoate, isobutyl isocaproate, ethyl 3-methylhexanoate, butyl 3-methylhexanoate, isobutyl 3-methylhexanoate, ethyl 2-ethylhexanoate, propyl 2-ethylhexanoate, butyl 2-ethylhexanoate, isobutyl 2-ethylhexanoate, ethyl phenylacetate, propyl phenylacetate, isopropyl phenylacetate, butyl phenylacetate, isobutyl phenylacetate, ethyl naphthylacetate, propyl naphthylacetate, isopropyl naphthylacetate, butyl naphthylacetate, isobutyl naphthylacetate, methyl cyclohexylacetate, ethyl cyclohexylacetate, propyl cyclohexylacetate, isopropyl naphthylacetate, isopropyl naphthyl, Butyl cyclohexylacetate, isobutyl cyclohexylacetate, methyl cyclopentylacetate, ethyl cyclopentylacetate, propyl cyclopentylacetate, isopropyl cyclopentylacetate, butyl cyclopentylacetate, isobutyl cyclopentylacetate, etc.

According to the method provided by the invention, the strong base is an organic metal compound and comprises potassium alkoxide, sodium alkoxide, lithium amide, sodium amide and potassium amide. Preferably selected from the following compounds: potassium methoxide, potassium ethoxide, potassium propoxide, potassium butoxide, potassium isobutoxide, potassium tert-butoxide, sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, sodium isobutanol, sodium tert-butoxide, lithium diethylamide, lithium dipropylamide, Lithium Diisopropylamide (LDA), lithium dibutylamide, lithium diisobutylaminide, sodium amide, potassium amide. Lithium Diisopropylamide (LDA) was chosen for convenience and safety of use. The strong base used in the method can be a pure product thereof or a reaction mixed liquid obtained in the preparation of the strong base.

In the method provided by the invention, the solvent is a low-melting-point aprotic solvent; the low-melting-point aprotic solvent is selected from one or more of ether, nitrile, halogenated hydrocarbon, aromatic hydrocarbon, alkane and cycloalkane. The aprotic solvent is further selected from one or more of diethyl ether, isopropyl ether, 1, 2-dimethoxyethane, tetrahydrofuran, acetonitrile, dichloromethane, dichloroethane, toluene, ethylbenzene, pentane, hexane, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, dimethylcyclohexane.

In the process provided by the invention, the oxidant is a transition metal compound in an oxidized state, such as titanium tetrachloride.

The method provided by the invention comprises the following steps: strong base: the oxidizing agent can be chosen within a wide range, preferably 1: 1-5: 1-5; the reaction temperature is-100 to 20 ℃, preferably-90 to-20 ℃. The initial concentration of each raw material in the reaction for preparing the 2, 3-alkyl substituted succinic diester can be carried out in a wide range, and the concentration of the carboxylic ester is preferably 0.05-10M, the concentration of the strong base is preferably 0.05-10M, and the concentration of the oxidant is preferably 0.05-10M.

In the prior art, the synthesis of the 2, 3-alkyl substituted diester succinate needs to be carried out under low temperature, and an indirect cooling method which is complex in operation and difficult to realize industrialization is adopted. The method of the invention realizes the low temperature condition, uses the liquid nitrogen which is inert to the chemical reaction as the refrigerant, directly introduces the liquid nitrogen into the reactor, directly cools the reaction liquid, achieves the low temperature condition required by the reaction, is easy to control the reaction temperature, saves the energy and is easy to realize the industrial production; the liquid nitrogen directly introduced into the reaction system can be used as inert protective gas after being gasified to replace other inert protective gas, so that the operation cost is reduced, the reaction device is simplified, and the operation is simplified. According to the method for preparing the 2, 3-alkyl substituted diester succinate, the enolate serving as the intermediate product is not required to be separated and purified, and the oxidant can be directly added for the next step of oxidative coupling reaction, so that the method has the advantages of simplicity in operation, simplicity in reaction device and the like. In addition, since olefin polymerization catalysts often require two or more internal electron donors to provide the catalysts with new properties, different 2, 3-hydrocarbyl substituted succinic diester mixtures may be used as electron donors, starting from the 2, 3-hydrocarbyl substituted succinic diester compound as the electron donor of the olefin polymerization catalyst. The method provided by the invention can adopt more than two carboxylic esters with different structures to carry out cross oxidation coupling to obtainThe product of (2) is a mixture of different 2, 3-alkyl substituted succinates, and can meet the requirements of olefin polymerization catalysts on different electron donors. The method of the invention can directly synthesize compounds containing different 2, 3-alkyl substituted succinates, such as 2, 3-non-alkyl substituted succinate, 2, 3-same dialkyl substituted succinate or 2, 3-same tetraalkyl substituted succinate when single fatty acid ester is used for oxidative coupling; when two fatty acid esters are used for the oxidative coupling, 2, 3-monohydrocarbyl-substituted succinic acid esters and/or 2, 3-trihydrocarbyl-substituted succinic acid esters (three different hydrocarbyl groups), or even two R's, can be obtained₃Or may be different from each other. As the alkyl groups in the structure of the general formula I are the same or different, the method has important significance for the synthesis of olefin polymerization catalysts; the method for synthesizing the succinate with various structures is very beneficial to industrial production. Therefore, another object of the present invention is to use the 2, 3-hydrocarbyl-substituted succinic acid diester prepared by the method of the present invention as an electron donor for an olefin polymerization catalyst.

Detailed Description

The following examples are presented to enable one of ordinary skill in the art to more fully understand the present invention and are not intended to limit the invention in any way.

Example 1

Preparation of dibutyl 2, 3-diisopropylsuccinate

Adding 135ml of LDA synthetic reaction solution with the concentration of 1.3mol/L and 135ml of Tetrahydrofuran (THF) into a stainless steel reactor with a vacuum heat-preservation interlayer, directly introducing liquid nitrogen into the mixed solution under stirring, dropwise adding the mixed solution of 0.15mol of butyl isovalerate and 150ml of THF into the reactor when the temperature is about-80 ℃, adjusting the introduction amount of liquid nitrogen to keep the reaction temperature, and continuously stirring for reacting for 1 hour. At this temperature, 0.27mol TiCl₄And 240mlCH₂Cl₂The mixed solution of (A) is added dropwise to the reaction solution, and then stirred and invertedAnd the time is 2 hours. After the reaction, 50ml of water was added to quench the reaction. In the reaction process, liquid nitrogen is gasified and then is used as protective gas of the reaction system.

After the reaction was completed, the temperature of the reactor was slowly raised to room temperature, and the reaction solution was extracted with 20ml of × 3 ethyl acetate and 60ml of 5% NaHCO₃The combined organic phases are neutralized, washed in solution and then washed with water until the organic phase is neutral. Drying with anhydrous magnesium sulfate, filtering, and distilling off solvent at normal pressure; the product was again distilled under reduced pressure to collect a dibutyl 2, 3-diisopropylsuccinate fraction at 140 ℃/2mmHg to give 15.28g of a yellow viscous oil of 95.5% purity by gas chromatography. The yield of dibutyl 2, 3-diisopropylsuccinate was 83.6%.

Examples 2 to 7

In examples 2 to 7, ethyl isovalerate, isobutyl isovalerate, isopropyl isovalerate, butyl butyrate, butyl isobutyrate, and isobutyl propionate were used instead of butyl isovalerate in example 1, and the procedure was otherwise the same as in example 1. The results are shown in Table 1.

TABLE 1

Example 8

The other steps were the same as in example 1 except that toluene was used as a solvent instead of tetrahydrofuran. The yield of dibutyl 2, 3-diisopropylsuccinate was 44.56%.

Example 9

The procedure of example 1 was repeated except that the tetrahydrofuran solution of isobutyl isovalerate was replaced with a tetrahydrofuran solution of butyl isovalerate mixed with butyl butyrate. The gas chromatography analysis showed that the yield of dibutyl 2, 3-diethylsuccinate was 5.80%, that of dibutyl 2, 3-diisopropylsuccinate was 32.18%, and that of dibutyl 2-ethyl-3-isopropylsuccinate was 31.28%.

Example 10

Referring to the conditions of document CN1313869A, a polymerization catalyst using dibutyl 2, 3-diisopropylsuccinate as an internal electron donor was prepared, and the results of propylene polymerization are shown in Table 2.

TABLE 2 comparison of experimental values for polymerization of catalyst with succinate as internal electron donor prepared according to the present invention with literature values

	Content of succinate/%)	Content of Ti/%)	Activity/gPP/g	Bulk density g/ml of polypropylene	Isotactic/percent of polypropylene
						Literature value	17.4	4.60	62000	-	98.5
Test value	13.75	3.28	62500	0.42	97.3

Claims

1. The synthesis process of preparing 2, 3-alkyl substituted diester succinate with the structure as shown in the general expression I includes the reaction of carboxylate and strong alkali in solvent to form metal enol salt and the subsequent oxidizing coupling with oxidant, and features that: directly introducing liquid nitrogen into a reactor, directly cooling reaction liquid to ensure that the reaction temperature is-100-25 ℃, and vaporizing the liquid nitrogen in the reaction process to be used as inert protective gas of a reaction system; the carboxylic ester is at least 1 of carboxylic esters with a structure of a general formula II; the strong base is pure lithium diisopropylamide or reaction mixed liquid for preparing lithium diisopropylamide; the solvent is a low-melting-point aprotic solvent and is selected from one or more of ether, nitrile, halogenated hydrocarbon, aromatic hydrocarbon, alkane and cycloalkane; the oxidant is titanium tetrachloride; the carboxylic acid ester: strong base: the oxidant is 1: 1-5: 1-5; the concentration of the carboxylic ester is 0.05-10M, the concentration of the strong base is 0.05-10M, and the concentration of the oxidant is 0.05-10M;

wherein,

R₁、R₂each independently selected from H or C₁～C₂₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl;

2. The method of claim 1, wherein: the R is₁、R₂Each independently selected from H or C₁～C₁₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl;

R₃is selected from C₁～C₁₀The alkyl is straight chain alkyl, branched chain alkyl, cycloalkyl, chain alkyl cycloalkyl, cycloalkyl chain alkyl, aryl, chain alkyl aryl or aryl chain alkyl.

3. The method of claim 1, wherein: the aprotic solvent is selected from one or more of diethyl ether, isopropyl ether, 1, 2-dimethoxyethane, tetrahydrofuran, acetonitrile, dichloromethane, dichloroethane, toluene, ethylbenzene, pentane, hexane, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, and dimethylcyclohexane.

4. The method according to any one of claims 1 to 3, wherein: introducing liquid nitrogen into the reactor to directly cool the reaction liquid to ensure that the reaction temperature is between 90 ℃ below zero and 20 ℃ below zero, and vaporizing the liquid nitrogen in the reaction process to be used as inert protective gas of the reaction system.