CN108863811A - A kind of high yield N, N- diethyl ethylenediamine preparation method - Google Patents

Abstract

The invention discloses a high-yield N,N-diethylethylenediamine preparation method. The method is to add 2-diethylaminochloroethane hydrochloride and benzyl carbamate into sodium hydroxide solution , add a palladium-carbon catalyst, heat to 55-65 ° C under sealed conditions and react for 4-7h, add alkali to the reaction solution to lower the temperature and alkali analysis, separate the lower layer of lye and palladium-carbon catalyst, and carry out rectification treatment on the organic layer, Collect the distillate at 142-148°C to obtain N,N-diethylethylenediamine. The method has mild reaction conditions, does not use or generate any harmful gas in the reaction process, and simultaneously has a high yield of N,N-diethylethylenediamine.

Description

A kind of high yield N,N-diethylethylenediamine preparation method

technical field

The invention belongs to the technical field of organic synthesis, and specifically relates to a preparation method of N,N-diethylethylenediamine.

Background technique

N,N-Diethylethylenediamine is a colorless and transparent liquid with a boiling point of 145.2°C. It is an important fine chemical intermediate and can be used as a pharmaceutical intermediate, surfactant, auxiliary agent, curing agent, etc., and has a wide range of uses.

At present, N,N-diethylethylenediamine is mainly prepared by the following methods: one is to use diethylamine and acrylamide as raw materials, and obtain N,N-diethylethylenediamine through addition and Hoffman rearrangement reaction. Diamine, but this method has extremely low storage and recovery rate, cumbersome operation, high equipment requirements, and the probability of side reactions increases with the passage of time and the increase of temperature. The 2nd is to react with ethylenediamine and bromoethylamine bromate, under the existence of copper ion, react and generate N,N-diethylethylenediamine, this method yield can reach 80%, and raw material cost is high, the 3rd is Using diethylamine and 2-chloroethylamine hydrochloride as raw materials, and using cuprous chloride as a catalyst for high-temperature and high-pressure reaction, N,N-diethylethylenediamine is finally obtained. The yield of this method reaches 78.6%, and the purity is Reach 99.2%, but still there is raw material cost high, and reaction condition is harsh, and sodium methylate has greater danger. Fourth, ethylenediamine is monoacetylated, alkylated, and then hydrolyzed to obtain the product. This method has high raw material costs, and there are highly toxic substances. The operation is cumbersome and the side reactions are large. The fifth is other methods, such as acrylonitrile obtained by hydrolysis, addition, and degradation, which is referred to by hydrogenation of ethylenediaminoacetonitrile. Both of these methods have high raw material costs, cumbersome operations, and methods that require high temperature and high pressure conditions. The sixth is to first synthesize 2-diethylamino ethyl chloride hydrochloride with diethylamino ethanol and chlorination reagents, and then react with liquid ammonia to obtain N,N-diethylethylenediamine. Although this method is more advanced than the previous method The yield is high, and the cost of raw materials is low, but in the second step reaction process, it still needs to be under a certain pressure (0.4-0.6MPa in the examples), and the recovery of gaseous substances is involved, which increases the preparation steps.

Contents of the invention

The object of the present invention is to address the shortcomings of the above-mentioned method for preparing N,N-diethylethylenediamine, and provide a method for preparing N,N-diethylethylenediamine that does not require gaseous substance treatment, has mild reaction conditions, and high yield. method.

In order to achieve the purpose of the present invention, through a large number of experimental studies and unremitting efforts, the following technical scheme is finally obtained: a high-yield N,N-diethylethylenediamine preparation method, the 2-diethylamino ethyl chloride salt Add salt and benzyl carbamate to sodium hydroxide solution, add palladium-carbon catalyst, heat to 55-65°C under sealed conditions to react for 4-7h, add alkali to the reaction solution to cool down and analyze alkali, and separate the lower layer of lye and palladium-carbon catalyst, the organic layer is rectified, and the fraction at 142-148°C is collected to obtain N,N-diethylethylenediamine.

Preferably, the high-yield N,N-diethylethylenediamine preparation method described above, wherein the molar ratio of 2-diethylamino ethyl chloride hydrochloride to benzyl carbamate is 1:(1.05 -1.10).

Preferably, the high-yield N,N-diethylethylenediamine preparation method described above, wherein the concentration of the sodium hydroxide solution is 40-60wt%.

Preferably, as mentioned above, the high-yield N,N-diethylethylenediamine preparation method, wherein the 2-diethylamino ethyl chloride hydrochloride and the mole of sodium hydroxide in the sodium hydroxide solution The ratio is 1: (10-60).

Preferably, in the high-yield N,N-diethylethylenediamine preparation method as described above, the alkali used for alkali analysis is one of sodium hydroxide, potassium hydroxide, and barium hydroxide.

Preferably, in the high-yield N,N-diethylethylenediamine preparation method as described above, the alkali precipitation temperature is controlled within 40°C.

Preferably, as mentioned above, the high-yield N,N-diethylethylenediamine preparation method, wherein the 2-diethylamino ethyl chloride hydrochloride can be prepared according to the following process: the chlorination reagent and diethyl Aminoethanol is incubated and reacted in the reaction solvent, then the reaction solvent is concentrated, and after concentration, low molecular weight alcohol or ester is added to recrystallize to obtain the wet product of 2-diethylaminochloroethane hydrochloride, which is dried to obtain 2-diethylaminochloride Ethane hydrochloride dry product.

Preferably, the high-yield N,N-diethylethylenediamine preparation method as described above, wherein the chlorination reagent is sulfur oxychloride, phosphorus pentachloride, phosphorus trichloride, NCS, chlorine gas, phosgene In one, the molar ratio of the chlorination reagent to diethylaminoethanol is (1.5-5):1.

Preferably, the high-yield N,N-diethylethylenediamine preparation method described above, wherein the reaction solvent is one of dichloromethane, chloroform, acetonitrile, benzene and its homologues, and carbon tetrachloride.

Compared with the prior art, the present invention has the following technical effects:

(1) The reaction conditions of the present invention are mild, and the synthesis of N,N-diethylethylenediamine can be realized without changing the pressure during the reaction;

(2) do not adopt or produce any harmful gas in the reaction process of the present invention, processing step reduces, and cost is low;

(3) The yield of N,N-diethylethylenediamine prepared by the present invention reaches above 91.43%, and the detected titration content reaches above 99.57%.

Detailed ways

The technical solutions of the present invention are clearly and completely described below in conjunction with the examples. The following examples are only used to illustrate the present invention, and should not be regarded as limiting the protection scope of the present invention. In addition, those that do not indicate the specific technical operation steps or conditions in the examples are all carried out according to the techniques or conditions described in the literature in this field or according to the product instructions. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products, and the concentrations in the following examples all refer to mass percent concentrations.

Preparation of 2-diethylaminoethyl chloride hydrochloride: Add 260g of thionyl chloride and 240g of dichloromethane into a 1L reaction flask to cool down, and prepare 120g of diethylaminoethanol and 100g of dichloromethane in a 500ml beaker during the cooling process. For the mixed solution of methyl chloride, when the temperature in the reaction bottle drops to -10°C, keep the temperature in the range of -10°C to 20°C and add the mixed solution of diethylaminoethanol and methylene chloride dropwise, and then raise the temperature to 35°C Insulate the reaction for 2.5 hours, then concentrate the dichloromethane until nothing comes out, then cool down to 24°C after concentration, add 220g of anhydrous methanol to the reaction bottle and heat to dissolve the solid, and cool the ice salt water to -8°C after the solid is completely dissolved. Crystallization for 7 hours, suction filtration to obtain the wet product of 2-diethylaminochloroethane hydrochloride, continue to concentrate and recover methanol after collecting the mother liquor, freeze and crystallize the raffinate for 24 hours, obtain the mother liquor product by suction filtration, and recrystallize the mother liquor product with methanol , drying the obtained 2-diethylamino ethyl chloride hydrochloride at 55-60°C to obtain a dry product, the liquid phase purity is 99.74%, and the molar yield is 98.08%.

Example 1 N, N-diethylethylenediamine preparation method:

Get 173.0g 2-diethylamino ethyl chloride hydrochloride and 159.55g benzyl carbamate and join in sodium hydroxide solution, the concentration of sodium hydroxide solution is 40wt%, 2-diethylamino ethyl chloride salt The molar ratio of sodium hydroxide to sodium hydroxide solution is 1:10, then add 8.65g of palladium-carbon catalyst, heat to 55°C for 7 hours under sealed conditions, add solid sodium hydroxide to the reaction solution to cool down and conduct alkali analysis , the alkali analysis temperature is 35°C, separate the lower layer of lye and palladium-carbon catalyst, carry out rectification treatment on the organic layer, collect the distillate at 142-148°C to obtain N,N-diethylethylenediamine.

Embodiment 2 N, the preparation method of N-diethylethylenediamine:

Get 200g 2-diethylamino ethyl chloride hydrochloride and 193.23g benzyl carbamate and join in the sodium hydroxide solution, the concentration of sodium hydroxide solution is 60wt%, 2-diethylamino ethyl chloride hydrochloride The molar ratio of salt to sodium hydroxide in the sodium hydroxide solution is 1:60, then add palladium-carbon catalyst, the addition amount is 8% of the mass of 2-diethylaminochloroethane hydrochloride, under sealed condition Heating to 65°C for 4 hours, adding solid sodium hydroxide to the reaction solution to cool down and alkali analysis, the temperature of alkali analysis is 25°C, separate the lower layer of alkali solution and palladium-carbon catalyst, carry out rectification treatment on the organic layer, and collect 142-148 The fraction at °C yields N,N-diethylethylenediamine.

Embodiment 3 N, the preparation method of N-diethylethylenediamine:

Get 250g 2-diethylamino ethyl chloride hydrochloride and 237.15g benzyl carbamate and join in the sodium hydroxide solution, the concentration of sodium hydroxide solution is 50wt%, 2-diethylamino ethyl chloride hydrochloride The molar ratio of salt to sodium hydroxide in the sodium hydroxide solution is 1:40, then add palladium-carbon catalyst, the addition amount is 5% of the mass of 2-diethylaminochloroethane hydrochloride, under sealed condition Heating to 60°C for 5 hours, adding solid potassium hydroxide to the reaction solution to reduce the temperature and alkali analysis, the alkali analysis temperature is 20°C, separate the lower layer of lye and palladium-carbon catalyst, carry out rectification treatment on the organic layer, and collect 142-148 The fraction at °C yields N,N-diethylethylenediamine.

Embodiment 4 N, the preparation method of N-diethylethylenediamine:

Get 173.0g 2-diethylamino ethyl chloride hydrochloride and 151.95g benzyl carbamate and join in sodium hydroxide solution, the concentration of sodium hydroxide solution is 40wt%, 2-diethylamino ethyl chloride salt The molar ratio of sodium hydroxide to the sodium hydroxide solution in the sodium hydroxide solution is 1:10, then add the palladium-carbon catalyst, and the addition amount is 5% of the mass of 2-diethylaminochloroethane hydrochloride. Heating to 55°C for 7 hours under the conditions, adding solid potassium hydroxide to the reaction liquid to cool down and alkali analysis, the alkali analysis temperature is 35°C, separate the lower layer alkali solution and palladium-carbon catalyst, carry out rectification treatment on the organic layer, and collect 142- The fraction at 148°C gave N,N-diethylethylenediamine.

Embodiment 5 N, the preparation method of N-diethylethylenediamine:

Get 173.0g 2-diethylamino ethyl chloride hydrochloride and 174.75g benzyl carbamate and join in sodium hydroxide solution, the concentration of sodium hydroxide solution is 50wt%, 2-diethylamino ethyl chloride salt The molar ratio of sodium hydroxide salt to the sodium hydroxide solution is 1:30, then add the palladium-carbon catalyst, the addition amount is 8% of the quality of 2-diethylaminochloroethane hydrochloride, in the sealed Heating to 55-65°C under conditions for 4-7h reaction, adding solid barium hydroxide to the reaction liquid to cool down and alkali analysis, the alkali analysis temperature is 30°C, separate the lower layer of lye and palladium-carbon catalyst, and carry out rectification treatment on the organic layer , Collecting fractions at 142-148°C to obtain N,N-diethylethylenediamine.

Example 6

The N,N-diethylethylenediamine obtained by the experiments of Examples 1-5 and the theoretically obtained amount are counted, and the results are shown in Table 1

Table 1 Statistics of N,N-diethylethylenediamine

project Example 1 Example 2 Example 3 Example 4 Example 5 Theoretical output (g) 116.8 135.0 168.8 116.8 116.8 Actual output (g) 106.8 124.0 155.9 104.2 102.5 Yield (%) 91.43 91.85 92.36 89.21 87.76 Detection titration content (%) 99.57 99.62 99.65 99.47 99.43

Comparative example 1 (do not add palladium-carbon catalyst)

On the basis of Example 1, no palladium-carbon catalyst was added, and other conditions remained unchanged. As a result, the calculated yield of N,N-diethylethylenediamine was only 27.58%.

Comparative example 2 (reaction temperature is lower than limit range)

On the basis of Example 1, the reaction temperature was changed to 50° C., and the other conditions remained unchanged. As a result, the calculated yield of N,N-diethylethylenediamine was only 76.82%.

Claims (9)

1. a kind of high yield N, the preparation method of N-diethylethylenediamine is characterized in that, 2-diethylamino ethyl chloride hydrochloride and benzyl carbamate are joined in the sodium hydroxide solution, Add palladium-carbon catalyst, heat to 55-65°C under sealed conditions to react for 4-7h, add alkali to the reaction solution to cool down and analyze alkali, separate the lower layer of alkali solution and palladium-carbon catalyst, carry out rectification treatment on the organic layer, collect The fraction at 142-148°C yields N,N-diethylethylenediamine. 2. according to the described high yield N of claim 1, the preparation method of N-diethylethylenediamine is characterized in that, the mol ratio of described 2-diethylamino ethyl chloride hydrochloride and benzyl carbamate is 1: (1.05-1.10). 3. The method for preparing high-yield N,N-diethylethylenediamine according to claim 1, wherein the concentration of the sodium hydroxide solution is 40-60wt%. 4. according to the described high-yield N of claim 1, the preparation method of N-diethylethylenediamine is characterized in that, in described 2-diethylamino ethyl chloride hydrochloride and described sodium hydroxide solution The molar ratio of sodium hydroxide is 1:(10-60). 5. according to the described high-yield N of claim 1, the preparation method of N-diethylethylenediamine is characterized in that, alkali analysis used alkali is a kind of in sodium hydroxide, potassium hydroxide, barium hydroxide. 6. The method for preparing high-yield N,N-diethylethylenediamine according to claim 1, characterized in that, the alkali precipitation temperature is controlled within 40°C. 7. according to the described high-yield N of claim 1, the preparation method of N-diethylethylenediamine is characterized in that, described 2-diethylamino ethyl chloride hydrochloride can be prepared according to the following process: chlorine Chemical reagent and diethylaminoethanol are incubated and reacted in the reaction solvent, then the reaction solvent is concentrated, and after concentration, low molecular alcohol or ester is added to recrystallize to obtain the wet product of 2-diethylaminoethyl chloride hydrochloride, which is dried to obtain 2- Diethylamino ethyl chloride hydrochloride dry product. 8. according to the described high-yield N of claim 7, the preparation method of N-diethylethylenediamine is characterized in that, described chlorination reagent is sulfur oxychloride, phosphorus pentachloride, phosphorus trichloride, NCS , chlorine, phosgene, the molar ratio of the chlorination reagent to diethylaminoethanol is (1.5-5):1. 9. according to the described high-yield N of claim 7, the preparation method of N-diethylethylenediamine is characterized in that, described reaction solvent is dichloromethane, chloroform, acetonitrile, benzene and homologue, carbon tetrachloride One of a kind.