Summary of the invention
The object of the present invention is to provide the new purposes of lithium diisopropylamine, i.e. application in preparation 1-methylcyclopropene.
Lithium diisopropylamine (LDA) can play the deprotonation effect to the carbonyl compound (comprising carboxylic acid, ester, aldehyde and ketone) of the most pure and mild α of containing-hydrogen.In tetrahydrofuran solution, lithium diisopropylamine (LDA) mainly exists with dimeric form, and can resolve into monomer when other materials of its deprotonation in advance.The present invention utilizes the character of lithium diisopropylamine (LDA), and it can be made 2-methylallyl chloride self cyclization as catalyzer, obtains the 1-methylcyclopropene.
In above-mentioned application process, the preparation process of described lithium diisopropylamine is: with Diisopropylamine, metallic lithium is raw material, add in the solvent earlier, be to drip auxiliary agent under 0 ℃~40 ℃ the condition in temperature, being warming up to 40~60 ℃ reacts, when the color of question response system becomes a kind of in grey, black, blueness, the mazarine, be cooled to continue under 0~40 ℃ the condition reaction 0.5~10 hour lithium diisopropylamine; The weight ratio of wherein said Diisopropylamine and metallic lithium is 5~20: 1; The weight ratio of described Diisopropylamine and solvent is 1: 1~5; The weight ratio of described Diisopropylamine and auxiliary agent is 1~3: 1.Adopt Diisopropylamine in the presence of auxiliary agent, to make lithium diisopropylamine (LDA),, reduced a large amount of energy consumptions like this because this step has relatively mild reaction conditions; The metallic lithium consumption is less in the reaction, can reduce the generation of lithium salts like this, can reduce simultaneously the consumption of solvent, and because the existence of auxiliary agent is arranged, and reaction can stable carrying out, and side reaction is few.
In above-mentioned application process, described solvent is one or more in ether, 2-methyltetrahydrofuran, tetrahydrofuran (THF), benzene, hexanaphthene, the methyl tertiary butyl ether, and described auxiliary agent is one or more in vinylbenzene, Tetramethyl Ethylene Diamine, hexamethylphosphoramide, the toluene.As preferably, described solvent is a kind of in ether, 2-methyltetrahydrofuran, the tetrahydrofuran (THF); Described auxiliary agent is a vinylbenzene.
In above-mentioned application process, as preferably, the temperature that drips auxiliary agent is 35~38 ℃, is warming up to 55~58 ℃, is cooled to 35~38 ℃.
In above-mentioned application process, the application process of described lithium diisopropylamine is: the application process of described lithium diisopropylamine is: be under 20 ℃~30 ℃ the condition in temperature, drip the 2-methylallyl chloride in the solvent of lithium diisopropylamine or in its reaction system, dropwising the back continues to stir 1~2 hour, add entry, collect gas and obtain the 1-methylcyclopropene, wherein the mol ratio of lithium diisopropylamine and 2-methylallyl chloride is 0.5~2: 1; Lithium diisopropylamine and water mol ratio are 1: 1~3.The present invention generates after the 1-MCP with the cyclization of lithium diisopropylamine (LDA) catalysis 2-methylallyl chloride, available distillatory method reclaims materials such as solvent, Diisopropylamine, auxiliary agent, carry out recycled, residuum is the chlorination lithium salts substantially, thereby reduced the discharging of waste liquid pollution on the environment, meet the cleaner production requirement, cost is reduced significantly.
In above-mentioned application process, as preferably, the temperature the during application process of lithium diisopropylamine is 25 ℃~28 ℃.
The reaction equation that the preparation of lithium diisopropylamine of the present invention and application lithium diisopropylamine catalysis 2-methylallyl chloride generate the 1-methylcyclopropene is as follows:
In sum, the present invention has the following advantages:
Application in preparation 1-methylcyclopropene preferably resolves that to produce in the 1-methylcyclopropene process of producing product energy consumption big as catalyzer with lithium diisopropylamine in the present invention, content is low, the technical barrier that cost is high, simplified production technique, reduced production cost, 1-methylcyclopropene yield height.
Embodiment
Below by specific embodiment also in conjunction with the accompanying drawings, technical scheme of the present invention is described in further detail; But the present invention is not limited to these embodiment.
Embodiment 1: the preparation lithium diisopropylamine
With Diisopropylamine 170g, metallic lithium 12g adds in the 300ml tetrahydrofuran (THF), and under 37 ℃, beginning slowly drips 95g vinylbenzene, constantly carry out along with dripping, reaction system begins to heat up, and is warmed up to 56 ℃, and this moment, reaction system was a grey, begin cooling later on, keep 37 ℃ constant, continue to stir, react and generate lithium diisopropylamine after 6 hours.
Application Example 1
In the reaction system of embodiment 1,, slowly drip 1mol 2-methylallyl chloride by the frozen water cooling, this moment, temperature of reaction was 26 ℃, continued to stir, and solution is creamy white, after dropwising, continue to stir, solution is oyster white, react after 1.5 hours, add 2mol water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, yield is more than 50%, and the entire reaction schema as shown in Figure 1.
Embodiment 2: the preparation lithium diisopropylamine
With Diisopropylamine 170g, metallic lithium 12g adds in the 300ml anhydrous diethyl ether, and under 37 ℃, beginning slowly drips the 95g Tetramethyl Ethylene Diamine, constantly carry out along with dripping, reaction system begins to heat up, and is warmed up to 56 ℃, and this moment, reaction system was a grey, begin cooling later on, keep 37 ℃ constant, continue to stir, react and generate lithium diisopropylamine after 4 hours.
Application Example 2
In the reaction system of embodiment 2,, slowly drip 1mol 2-methylallyl chloride by the frozen water cooling, this moment, temperature of reaction was 26 ℃, continued to stir, and solution is creamy white, after dropwising, continue to stir, solution is oyster white, reacts after 1.5 hours, add 2mol water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, yield is more than 50%.
Embodiment 3: the preparation lithium diisopropylamine
With Diisopropylamine 180g, metallic lithium 10g adds in the 350ml tetrahydrofuran (THF), and under 20 ℃, beginning slowly drips 105g vinylbenzene, constantly carry out along with dripping, reaction system begins to heat up, and is warmed up to 45 ℃, and this moment, reaction system was a grey, begin cooling later on, keep 20 ℃ constant, continue to stir, react and generate lithium diisopropylamine after 8 hours.
Application Example 3
In the reaction system of embodiment 3,, slowly drip 1.5mol 2-methylallyl chloride by the frozen water cooling, this moment, temperature of reaction was 25 ℃, continued to stir, and solution is creamy white, after dropwising, continue to stir, solution is oyster white, reacts after 2 hours, add 3mol water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, yield is more than 50%.
Embodiment 4: the preparation lithium diisopropylamine
With Diisopropylamine 200g, metallic lithium 15g adds in the 400ml tetrahydrofuran (THF), and under 10 ℃, beginning slowly drips 110g vinylbenzene, constantly carry out along with dripping, reaction system begins to heat up, and is warmed up to 58 ℃, and this moment, reaction system was a grey, begin cooling later on, keep 10 ℃ constant, continue to stir, react and generate lithium diisopropylamine after 10 hours.
Application Example 4
In the reaction system of embodiment 4,, slowly drip 1mol 2-methylallyl chloride by the frozen water cooling, this moment, temperature of reaction was 28 ℃, continued to stir, and solution is creamy white, after dropwising, continue to stir, solution is oyster white, reacts after 1 hour, add 1.5mol water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, yield is more than 50%.
Embodiment 5
With Diisopropylamine 170g, metallic lithium 12g adds in the 300ml 2-methyltetrahydrofuran, and under 37 ℃, beginning slowly drips 95g vinylbenzene, constantly carry out along with dripping, reaction system begins to heat up, and is warmed up to 56 ℃, and this moment, reaction system was a grey, begin cooling later on, keep 37 ℃ constant, continue to stir, react and generate lithium diisopropylamine after 2 hours.
Application Example 5
In the reaction system of embodiment 5,, slowly drip 1mol 2-methylallyl chloride by the frozen water cooling, this moment, temperature of reaction was 26 ℃, continued to stir, and solution is creamy white, after dropwising, continue to stir, solution is oyster white, reacts after 1.5 hours, add 2mo l water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, yield is more than 50%.
Comparative example 1
Under nitrogen protection; earlier metallic lithium 14.3g is dropped in the 200ml anhydrous diethyl ether of-15 degree; slowly drip ready n-propylcarbinyl chloride (92.5g then; the dilution of 200ml anhydrous diethyl ether); after adding, be incubated-10 ℃ of half an hour, be warmed up to 0~5 ℃ then and stirred 2 hours; under the last nitrogen protection, suction filtration is removed the solid lithium chloride.Get the diethyl ether solution of n-Butyl Lithium, yield 85%.
Use comparative example 1
The n-Butyl Lithium diethyl ether solution frozen water that filtration obtains is lowered the temperature, slowly drip the 76.5g2-methylallyl chloride, control reaction temperature is no more than 26 ℃, after dropwising, continues to stir, solution is creamy white, behind the question response 1.5 hours, add 36g water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, 1-methylcyclopropene gas reaction yield is lower than 40%.
Comparative example 2
Under nitrogen protection; earlier in the 200ml anhydrous diethyl ether (solvent) with-15 ℃ of metallic lithium 14.3g inputs; slowly drip ready n-propylcarbinyl chloride (92.5g then; the dilution of 200ml anhydrous diethyl ether); after adding, be incubated-10 ℃ of half an hour, be warmed up to 0 ~ 5 ℃ of stirring then and obtained n-Butyl Lithium in 2 hours; this solution is desalination not, directly prepares to carry out next step reaction.
Use comparative example 2
The diethyl ether solution frozen water of above-mentioned n-Butyl Lithium is cooled, slowly drip the 76.5g2-methylallyl chloride, control reaction temperature is no more than 26 ℃, after dropwising, carefully add 36g water, have a large amount of bubbles to emerge, collect the 1-methylcyclopropene gas, 1-methylcyclopropene yield only is 20%.
Specific embodiment described in the present invention only is that the present invention's spirit is illustrated.The technician of the technical field of the invention can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present invention or surmount the defined scope of appended claims.
Although the present invention has been made detailed explanation and has quoted some specific embodiments as proof, to those skilled in the art, only otherwise leave that the spirit and scope of the present invention can be done various variations or correction is obvious.