CN103319342A - Method for synthesizing ethyl oleate - Google Patents

Abstract

The invention discloses a method for synthesizing ethyl oleate. The method is characterized by comprising the following steps: carrying out an esterification reaction between oleic acid and ethanol in the presence of an H2SO4/SiO2 immobilized catalyst, filtering the reaction solution, and purifying or distilling the filtrate through column chromatography to obtain colorless or faint yellow clarified liquid ethyl oleate, wherein the molar ratio of oleic acid to ethanol is 1: (1.5-5); and the molar ratio of the catalyst to oleic acid is 1: (10-50). Compared with the prior art, the method has the advantages that the method is simple in process, convenient to operate, low in production cost, high in yield and mild in reaction conditions, the consumption of raw materials is further reduced, the yield can be improved to be over 95 percent, and the production cost is obviously reduced; and moreover, the catalyst can be recycled, the environment is not polluted, and the method is an ethyl oleate synthesizing method which is environment-friendly, economic and high-efficiency and has a good application prospect.

Description

A kind of synthetic method of ethyl oleate

Technical field

The present invention relates to the organic chemical synthesis technical field, specifically a kind of synthetic method of ethyl oleate.

Background technology

Ethyl oleate is the pale yellow oily liquid body, mainly as tensio-active agent, lubricant, permeate agent, solubility promoter, essence, water repellent agent and the agent of resin malleableize, also as spices.As raw material take oleic acid and ethanol for the synthetic most typical method of ethyl oleate, use sulfuric acid to carry out reflux 10h as catalyzer, being neutralized to pH with sodium methylate after the cooling is 8 ~ 9, then washes with water to neutrality, and at last, filtration dry with Calcium Chloride Powder Anhydrous makes.(Xu Kexun. meticulous Organic Chemicals and intermediate handbook. Beijing: Chemical Industry Press 1998,4:1 ~ 350).The method shortcoming is that the reaction times is oversize, and the product postprocessing working procedures is longer simultaneously, and industrial cost is higher.

Another kind of method commonly used is to adopt pickling process to prepare the carried phospho-tungstic acid mesoporous carbon as catalyzer (Tan Xiaoyu, Yang Lina, Liu Jing, Xu Junbo, the carried phospho-tungstic acid mesoporous carbon catalyzes and synthesizes the research of ethyl oleate. charcoal element, 2011,1 (145): 25 ~ 28).The method temperature of reaction is 110 ℃, and the phospho-wolframic acid charge capacity is 30%, reaction times 4h, and, the oleic acid ester rate is 89.34%.Although this method shortened to some extent than traditional preparation method's reaction times, temperature of reaction is higher, and the reaction times is also longer, and the preparation cost of catalyzer is higher and cannot reclaim and reuse.

In sum, the ethyl oleate of prior art preparation, synthesis technique is complicated, and environmental pollution is large, the widespread use that has seriously restricted.Therefore, be necessary to seek a kind of system milder, more economical, green ethyl oleate synthetic method, this is significant for ethyl oleate application aborning.

Summary of the invention

The synthetic method that a kind of ethyl oleate of providing for the deficiencies in the prior art is provided, recover the oil acid and ethanol are at H ₂SO ₄/ SiO ₂Carry out esterification under the solid-carrying type catalyzer, the reaction system of synthetic oil acetoacetic ester is gentle, easy and simple to handle, raw materials consumption reduces, productive rate can be brought up to more than 95%, and production cost obviously reduces, and the catalyzer aftertreatment simply can be recycled, free from environmental pollution, be a kind of environmental protection and economical and efficient and very promising ethyl oleate synthetic method.

The concrete technical scheme that realizes the object of the invention is: a kind of synthetic method of ethyl oleate, be characterized in the method with oleic acid and ethanol at H ₂SO ₄/ SiO ₂Carry out esterification under the solid-carrying type catalyzer, then reacting liquid filtering is removed catalyzer, filtrate is purified that colourless or faint yellow clarified liq is ethyl oleate, and concrete synthesis step is as follows:

The preparation of a, solid acid catalyst

With SiO ₂Solid and anhydrous methyl ether and concentration be 98% sulfuric acid by weight volume ratio be after 2g:4ml:1ml mixes, dry 4 ~ 5h under 130 ~ 140 ℃ of temperature, the fine powder that obtains light brown is H ₂SO ₄/ SiO ₂The solid-carrying type catalyzer;

B, esterification

Oleic acid is mixed for 1:1.5 ~ 5 in molar ratio with ethanol, then at the H of above-mentioned preparation ₂SO ₄/ SiO ₂Carry out 1 ~ 5 hour esterification under the solid-carrying type catalyzer, its temperature of reaction is 50 ~ 110 ℃; Described H ₂SO ₄/ SiO ₂The mol ratio of solid-carrying type catalyzer and oleic acid is 1:10 ~ 50;

C, purification

Leach catalyzer in the reaction solution with above-mentioned esterification, filtrate is purified through silica gel column chromatography or underpressure distillation, and obtaining colourless or light yellow transparent oily liquid is ethyl oleate.

It is simple, easy to operate that the present invention compared with prior art has technique, reaction conditions is gentle, productive rate can be brought up to more than 95%, further reducing raw materials consumption reduces, production cost obviously reduces, and catalyzer can be recycled, and is free from environmental pollution, is the synthetic method of a kind of environmental protection and economical and efficient and very promising ethyl oleate.

Description of drawings

Fig. 1 is infrared spectrogram of the present invention.

Embodiment

Below will the present invention is further elaborated by specific embodiment:

Embodiment 1

The preparation of a, solid acid catalyst

Take by weighing SiO ₂It is 98% sulfuric acid that solid 10.0g and 20.0ml anhydrous diethyl ether mix rear slow dropping 5ml concentration, need stir during dropping, after dripping with its ventilation, be positioned in the baking oven dry after allowing methyl ether volatilize, oven temperature is arranged on 135 ℃, and be 4h time of drying, and the fine powder that makes light brown is H ₂SO ₄/ SiO ₂The solid-carrying type catalyzer, stand-by.

B, esterification

H with 1.00ml oleic acid and 0.55ml ethanol and the above-mentioned preparation of 0.013g ₂SO ₄/ SiO ₂The solid-carrying type catalyzer mixes, and under agitation carries out esterification, and its temperature of reaction is 90 ℃, and the reaction times is 2.5 hours.

C, purification

With the reacting liquid filtering of above-mentioned esterification, the catalyzer that leaches can be recycled, and filtrate is purified through silica gel column chromatography, makes the ethyl oleate 0.981g of achromaticity and clarification liquid, and its productive rate is 91.4%, records refractive index n ²⁰ _D=1.4532.

Nuclear-magnetism spectrum test data is as follows: ¹H-NMR (500MHz, CDCl ₃): δ (ppm) 5.34 (m, 2H), 4.12 (q, J=7.2Hz, 2H), 2.28 (t, J=7.5Hz, 2H), 1.62 (m, 2H), 1.24-1.31 (m, 24H), 0.89 (t, J=6.0Hz, 3H).

To above-mentioned products therefrom ethyl oleate after testing, can confirm as pure target product after analyzing.

Embodiment 2

The preparation of a, solid acid catalyst

Take by weighing SiO ₂It is 98% sulfuric acid that solid 10.0g and 20.0ml anhydrous diethyl ether mix rear slow dropping 5ml concentration, need stir during dropping, after dripping with its ventilation, be positioned in the baking oven dry after allowing methyl ether volatilize, oven temperature is arranged on 140 ℃, and be 3.5h time of drying, and the fine powder that makes light brown is H ₂SO ₄/ SiO ₂The solid-carrying type catalyzer, stand-by.

B, esterification

H with 50.0ml oleic acid and 20.0ml ethanol and the above-mentioned preparation of 1.9g ₂SO ₄/ SiO ₂The solid-carrying type catalyzer mixes, and under agitation carries out esterification, and its temperature of reaction is 110 ℃, and the reaction times is 1.5 hours.

C, purification

Filter reaction system after esterification finishes, filtrate obtains faint yellow clarified liq ethyl oleate 46.7g through underpressure distillation.(bp:205～208 ℃/7mmHg) the ethyl oleate theoretical yield is 49.0g, and the productive rate that historical facts or anecdotes is tested middle ethyl oleate is 95.3%, records sample refractive index n ²⁰ _D=1.4538.

Consult accompanying drawing 1, above-mentioned products therefrom ethyl oleate is carried out infrared spectra detect, its data are as follows: 3006.67cm ^-1Vibration absorption peak for C-H on the two keys of ethyl oleate C=C; 2926cm ^-1And 2854.96cm ^-1C-H stretching vibration absorption peak for methyl and methylene radical; 1738.09cm ^-1Be C=O ester carbonyl stretching vibration absorption peak; 1178.78cm ^-1, 1036.03cm ^-1Asymmetric stretching vibration absorption peak for the C-O-C key; 1462.38cm ^-1, 1383.78cm ^-1C-H flexural vibration absorption peak for methyl and methylene radical; 980cm ^-1～650cm ^-1The peak at place is a plurality of CH ₂The absorption peak that its C-H out-of-plane deformation vibration produces when becoming straight chain.Test measured ir data and document (Ling Guanting, Tang Shuchao, Tao Minqiang. foodstuff additive handbook [M]. the third edition. Beijing: Chemical Industry Press, 2003.411-412) the main group infrared signature absorption of middle ethyl oleate is consistent, illustrates that this product is ethyl oleate.

More than just the present invention is further illustrated, is not to limit this patent, all for the present invention's equivalence enforcement, all should be contained within the claim scope of this patent.

Claims (1)

1. the synthetic method of an ethyl oleate, it is characterized in that the method with oleic acid and ethanol at H ₂SO ₄/ SiO ₂Carry out esterification under the solid-carrying type catalyzer, then with reacting liquid filtering, filtrate is through purifying to such an extent that faint yellow clarified liq is ethyl oleate, and concrete synthesis step is as follows:

The preparation of a, solid acid catalyst

With SiO ₂Solid and anhydrous diethyl ether and concentration be 98% sulfuric acid by weight volume ratio be after 2g:4ml:1ml mixes, dry 4 ~ 5h under 130 ~ 140 ℃ of temperature, the fine powder that obtains light brown is H ₂SO ₄/ SiO ₂The solid-carrying type catalyzer;

B, esterification

Oleic acid is mixed for 1:1.5 ~ 5 in molar ratio with ethanol, then at the H of above-mentioned preparation ₂SO ₄/ SiO ₂Carry out 1 ~ 5 hour esterification under the solid-carrying type catalyzer, its reaction oil bath temperature is 50 ~ 110 ℃; Described H ₂SO ₄/ SiO ₂The mol ratio of solid-carrying type catalyzer and oleic acid is 1:10 ~ 50;

C, purification

Leach catalyzer in the reaction solution with above-mentioned esterification, filtrate is purified through silica gel column chromatography or underpressure distillation, and obtaining colourless or light yellow transparent oily liquid is ethyl oleate.

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