Synthesis method of 2,2-dibromo-2-malonamidenitrile

Abstract

The invention discloses a synthesis method of 2,2-dibromo-2-malonamidenitrile. The synthesis method comprises the following steps of: adding malonamidenitrile and a solvent into a reaction bottle, wherein the malonamidenitrile is used as raw materials; dropwise adding liquid bromine while stirring at the reaction temperature of 15-45 DEG C, when the dropwise adding dosage of the malonamidenitrileaccounts for one third to four fifths of a total adding amount, beginning to dropwise adding hydrogen peroxide with the concentration of 30 percent, after dropwise adding the liquid bromine and the hydrogen peroxide, continuing reacting for 0.5-6 hours, and then filtering to obtain the 2,2-dibromo-2-malonamidenitrile, wherein the molar ratio of the malonamidenitrile to the bromine to the hydrogenperoxide is 1:(1.1-1.3):(0.70-0.90), the solvent is water or filtrate, and the dosage of the solvent is 252-420mL malonamidenitrile per mole. The invention is mainly used for the synthesis of the 2,2-dibromo-2-malonamidenitrile.

Description

technical field

[0001] The invention relates to a synthesis method of 2,2-dibromo-2-cyanoacetamide, which belongs to organic synthesis. Background technique

[0002] 2,2-Dibromo-2-cyanoacetamide, also known as dibromocyanoacetamide (DBNPA), is a new type of high-efficiency bactericide and algicide and water treatment agent, with high efficiency and broad spectrum, easy to degrade, and no residue It has the advantages of residual toxicity and no pollution to the environment, and at the same time has the functions of bactericidal and algae killing, viscidity and scale removal, and corrosion inhibition. It has broad application prospects and development value.

[0003] Usually, the synthetic method of 2,2-dibromo-2-cyanoacetamide uses bromate or chlorate as oxidizing agent, but this method generates by-product-salt, which is not easy to be mixed with 2,2-dibromo-2-cyanide Acetamide separation, the filtrate can not be reused. In order to solve this problem, the above-mentioned...

Examples

Embodiment 1

[0021] Add 84.1g (1.0mol) of cyanoacetamide and 252mL of water into a four-necked reaction flask, and add 192.7g (99.5%, 1.2mol) of liquid bromine dropwise under stirring at a reaction temperature of 20°C to 25°C. When the amount of addition is 2 / 3 of the total amount, start to add 80.7mL (30.5%, 0.8mol) of hydrogen peroxide dropwise. After the liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 1.5h, filter, and recover the filtrate. It is the product 2,2-dibromo-2-cyanoacetamide with a yield of 99.6%. The experiment was repeated four times under the same process conditions, and the reaction yields were 99.0%, 99.5%, 98.7%, and 99.3%, respectively, and the fluctuation range of the reaction yield was less than 1%.

Embodiment 2

[0023] Add 84.1g (1.0mol) of cyanoacetamide and 336mL of water into a four-necked reaction flask, and add 208.8g (99.5%, 1.3mol) of liquid bromine dropwise under stirring at a reaction temperature of 15°C to 20°C. When the amount added is 1 / 2 of the total amount, start to add 70.6mL (30.5%, 0.7mol) of hydrogen peroxide dropwise. After the liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 0.5h, filter, and recover the filtrate. It is the product 2,2-dibromo-2-cyanoacetamide with a yield of 98.4%.

Embodiment 3

[0025] Add 84.1g (1.0mol) of cyanoacetamide and 420mL of water into the four-necked reaction flask, and add 176.7g (99.5%, 1.1mol) of liquid bromine dropwise under stirring at a reaction temperature of 40°C to 45°C. When the addition amount is 1 / 3 of the total amount added, start to add 90.8mL (30.5%, 0.9mol) of hydrogen peroxide dropwise. After liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 4h, filter, and recover the filtrate. The filter cake is Product 2, 2-dibromo-2-cyanoacetamide, yield 82.7%.

technical field

[0001] The invention relates to a synthesis method of 2,2-dibromo-2-cyanoacetamide, which belongs to organic synthesis. Background technique

[0002] 2,2-Dibromo-2-cyanoacetamide, also known as dibromocyanoacetamide (DBNPA), is a new type of high-efficiency bactericide and algicide and water treatment agent, with high efficiency and broad spectrum, easy to degrade, and no residue It has the advantages of residual toxicity and no pollution to the environment, and at the same time has the functions of bactericidal and algae killing, viscidity and scale removal, and corrosion inhibition. It has broad application prospects and development value.

[0003] Usually, the synthetic method of 2,2-dibromo-2-cyanoacetamide uses bromate or chlorate as oxidizing agent, but this method generates by-product-salt, which is not easy to be mixed with 2,2-dibromo-2-cyanide Acetamide separation, the filtrate can not be reused. In order to solve this problem, the above-mentioned...

Examples

Embodiment 1

[0021] Add 84.1g (1.0mol) of cyanoacetamide and 252mL of water into a four-necked reaction flask, and add 192.7g (99.5%, 1.2mol) of liquid bromine dropwise under stirring at a reaction temperature of 20°C to 25°C. When the amount of addition is 2 / 3 of the total amount, start to add 80.7mL (30.5%, 0.8mol) of hydrogen peroxide dropwise. After the liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 1.5h, filter, and recover the filtrate. It is the product 2,2-dibromo-2-cyanoacetamide with a yield of 99.6%. The experiment was repeated four times under the same process conditions, and the reaction yields were 99.0%, 99.5%, 98.7%, and 99.3%, respectively, and the fluctuation range of the reaction yield was less than 1%.

Embodiment 2

[0023] Add 84.1g (1.0mol) of cyanoacetamide and 336mL of water into a four-necked reaction flask, and add 208.8g (99.5%, 1.3mol) of liquid bromine dropwise under stirring at a reaction temperature of 15°C to 20°C. When the amount added is 1 / 2 of the total amount, start to add 70.6mL (30.5%, 0.7mol) of hydrogen peroxide dropwise. After the liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 0.5h, filter, and recover the filtrate. It is the product 2,2-dibromo-2-cyanoacetamide with a yield of 98.4%.

Embodiment 3

[0025] Add 84.1g (1.0mol) of cyanoacetamide and 420mL of water into the four-necked reaction flask, and add 176.7g (99.5%, 1.1mol) of liquid bromine dropwise under stirring at a reaction temperature of 40°C to 45°C. When the addition amount is 1 / 3 of the total amount added, start to add 90.8mL (30.5%, 0.9mol) of hydrogen peroxide dropwise. After liquid bromine and hydrogen peroxide are added dropwise, continue the constant temperature reaction for 4h, filter, and recover the filtrate. The filter cake is Product 2, 2-dibromo-2-cyanoacetamide, yield 82.7%.

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