A kind of preparation method of n-alkylacrylamide

Abstract

The invention relates to a preparation method of N-alkyl acrylamides. The preparation method comprises the following steps: 1) under the catalysis of concentrated sulfuric acid, acrylonitrile reacts with an alpha-olefin to form an intermediate, wherein in the reaction process, the molar ratio of acrylonitrile, alpha-olefin and sulfuric acid is controlled to be 1:[0.9-1.1]:[1-1.2]; 2) water is added to the intermediate to perform hydrolysis, so as to obtain an upper layer hydrolysis product and a lower layer sulfuric acid solution; and 3) the upper layer hydrolysis product is purified to give the N-alkyl acrylamides. According to the preparation method, no organic acid is added as a cocatalyst, the sulfuric acid can be directly separated from the reaction product to obtain high-purity sulfuric acid, and the high-purity sulfuric acid can be directly reused after being concentrated, thereby eliminating the consumption of an alkali in the reaction process, and greatly reducing treatment cost of waste acid and production cost; and the yield of the target product is greater than 90%, the purity is greater than 98%, the reaction process is mild and easy to control, the source of raw materials is wide, and the product post-processing is simple, therefore, the N-alkyl acrylamides are easy for industrial production.

Description

technical field

[0001] The invention belongs to the field of synthesis of organic compounds, and in particular relates to a preparation method of N-alkylacrylamide. Background technique

[0002] Hydrophobic association Water-soluble polymers have a unique structure. In aqueous solution, due to the hydrophobic effect, the hydrophobic groups of the polymers aggregate, causing macromolecular chains to produce intramolecular and intermolecular associations, so they have good viscosity-increasing properties. Shear resistance, salt resistance, etc., are widely used in the fields of enhanced oil recovery, fluidity control and paint thickening.

[0003] There are four types of methods for the preparation of hydrophobic monomer N-alkylacrylamides that are hydrophobically associated with water-soluble polymers: (1) the reaction method of acryloyl chloride and alkylamine; (2) thermal decomposition of carboxylic acid or sulfonic acid amides (3) reaction method of olefin or alcohol and ...

Examples

Embodiment 1

[0039] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0040] 1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1:0.95:1, add 130.7g of concentrated sulfuric acid with a concentration of 75% to the equipment equipped with a condenser, thermometer, and agitator In the reactor, the temperature of the system was lowered to 5°C with an ice-water bath, and 53 grams of acrylonitrile and 159.9 grams of 1-dodecene were slowly added dropwise in sequence. During the dropping process, the reaction temperature did not exceed 8°C. , the temperature of the system was raised to 40°C, and the stirring reaction was continued for 3.5h; the reaction was completed, and an intermediate was obtained;

[0041] 2) Add 17.1 grams of deionized water to the monomer, stir evenly, let stand, and separate layers to obtain an upper layer solution and a lower layer solutio...

Embodiment 2

[0044] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0045]1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1:1:1.2, add 147g of concentrated sulfuric acid with a concentration of 80% into a container equipped with a condenser, a thermometer and a stirrer. In the reactor, the temperature of the system was lowered to 5°C in an ice-water bath, and 53 grams of acrylonitrile and 196 grams of 1-tetradecene were slowly added dropwise in sequence. During the dropwise addition, the reaction temperature did not exceed 8°C. After the dropwise addition, the system The temperature was raised to 40°C, and the stirring reaction was continued for 3.5 hours; the reaction was completed, and the monomer was obtained;

[0046] 2) Add 18 grams of deionized water to the intermediate, stir evenly, leave standstill, and separate layers to obtain an upper layer ...

Embodiment 3

[0049] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0050] 1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1: 1.1: 1.2, add 138.2 g of concentrated sulfuric acid with a concentration of 85% into a condenser, thermometer, and agitator In the reactor, the temperature of the system was lowered to 5°C with an ice-water bath, and 53 grams of acrylonitrile and 246.4 grams of 1-hexadecene were slowly added dropwise in sequence. During the dropwise addition, the reaction temperature did not exceed 8°C. After the dropwise addition, The temperature of the system was raised to 50°C, and the stirring reaction was continued for 6 hours; after the reaction was completed, an intermediate was obtained;

[0051] 2) Add 18 grams of deionized water to the intermediate, stir evenly, leave standstill, and separate layers to obtain an upper layer solution an...

technical field

[0001] The invention belongs to the field of synthesis of organic compounds, and in particular relates to a preparation method of N-alkylacrylamide. Background technique

[0002] Hydrophobic association Water-soluble polymers have a unique structure. In aqueous solution, due to the hydrophobic effect, the hydrophobic groups of the polymers aggregate, causing macromolecular chains to produce intramolecular and intermolecular associations, so they have good viscosity-increasing properties. Shear resistance, salt resistance, etc., are widely used in the fields of enhanced oil recovery, fluidity control and paint thickening.

[0003] There are four types of methods for the preparation of hydrophobic monomer N-alkylacrylamides that are hydrophobically associated with water-soluble polymers: (1) the reaction method of acryloyl chloride and alkylamine; (2) thermal decomposition of carboxylic acid or sulfonic acid amides (3) reaction method of olefin or alcohol and ...

Examples

Embodiment 1

[0039] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0040] 1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1:0.95:1, add 130.7g of concentrated sulfuric acid with a concentration of 75% to the equipment equipped with a condenser, thermometer, and agitator In the reactor, the temperature of the system was lowered to 5°C with an ice-water bath, and 53 grams of acrylonitrile and 159.9 grams of 1-dodecene were slowly added dropwise in sequence. During the dropping process, the reaction temperature did not exceed 8°C. , the temperature of the system was raised to 40°C, and the stirring reaction was continued for 3.5h; the reaction was completed, and an intermediate was obtained;

[0041] 2) Add 17.1 grams of deionized water to the monomer, stir evenly, let stand, and separate layers to obtain an upper layer solution and a lower layer solutio...

Embodiment 2

[0044] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0045]1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1:1:1.2, add 147g of concentrated sulfuric acid with a concentration of 80% into a container equipped with a condenser, a thermometer and a stirrer. In the reactor, the temperature of the system was lowered to 5°C in an ice-water bath, and 53 grams of acrylonitrile and 196 grams of 1-tetradecene were slowly added dropwise in sequence. During the dropwise addition, the reaction temperature did not exceed 8°C. After the dropwise addition, the system The temperature was raised to 40°C, and the stirring reaction was continued for 3.5 hours; the reaction was completed, and the monomer was obtained;

[0046] 2) Add 18 grams of deionized water to the intermediate, stir evenly, leave standstill, and separate layers to obtain an upper layer ...

Embodiment 3

[0049] This embodiment relates to the preparation method of N-alkylacrylamide described in the present invention, comprising the following steps:

[0050] 1) According to the ratio of n (acrylonitrile): n (α-olefin): n (concentrated sulfuric acid) = 1: 1.1: 1.2, add 138.2 g of concentrated sulfuric acid with a concentration of 85% into a condenser, thermometer, and agitator In the reactor, the temperature of the system was lowered to 5°C with an ice-water bath, and 53 grams of acrylonitrile and 246.4 grams of 1-hexadecene were slowly added dropwise in sequence. During the dropwise addition, the reaction temperature did not exceed 8°C. After the dropwise addition, The temperature of the system was raised to 50°C, and the stirring reaction was continued for 6 hours; after the reaction was completed, an intermediate was obtained;

[0051] 2) Add 18 grams of deionized water to the intermediate, stir evenly, leave standstill, and separate layers to obtain an upper layer solution an...

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