Method for preparing crystal form thioamino carboxylate by taking secondary amine as raw material

Abstract

The invention relates to a method for preparing crystal form thioamino carboxylate by taking secondary amine as a raw material, namely a method for preparing the crystal form thioamino carboxylate bya one-step method through a mixed reaction of the secondary amine, carbon disulfide, metal oxide or hydroxide in water. According to the scheme, conventional reaction equipment and simplified raw materials are used for preparing a high-purity product; the method is low in water consumption, inorganic salt byproducts are not generated, and the reaction mother liquor can be recycled directly or through simple treatment.

Description

technical field

[0001] The invention relates to the preparation technology of fine chemicals, in particular to a method for preparing crystalline thioaminocarboxylates from secondary amines. Background technique

[0002] Thioaminocarboxylates are a class of fine chemicals that are widely used. The global annual demand is more than 50,000 tons. They are mainly used as rubber vulcanization accelerators, polymer materials and petroleum polymerization inhibitors, lubricating oil anti-wear additives, and pesticides. Wait. In specific chemical reactions, it is also used as a synergistic additive and a polymerization terminator. It is also reported to be used in the formulation of zinc-containing precursor solutions for multi-element alloy quantum dots.

[0003] The disclosed preparation technology of this type of compound includes two-step alkali method and one-step method. The two-step alkali method is adopted by most production enterprises because of its high yield and mature t...

Examples

Embodiment 1

[0036] At room temperature, to 1m 3 Add 400kg of water, 34kg of nanometer zinc oxide (average particle size of electron microscope is 57nm), 0.68kg of RP-90 into the reactor, and mix well. Continue to add 32.5kg of carbon disulfide, and slowly add 45.0Kg of dimethylamine aqueous solution (40%); after the addition, add 32.5kg of carbon disulfide again, and add dropwise 45.0Kg of dimethylamine aqueous solution (40%). Gradually raise the temperature and react to weak reflux, and the reaction ends in 5.5 hours. separate. Obtaining white crystals is zinc dimethyl dithioaminocarboxylate, and the product is finely divided crystals, and its crystal form is shown in the attached figure 1 . The dry product has a yield of 99.3% based on amine and a purity of 99.3%. The ammonia nitrogen in the mother liquor is 17mg / L, and the chemical oxygen demand is 180mg / L.

Embodiment 2

[0038] At room temperature, to 1m 3 Add 400kg of water, 43.0kg of zinc hydroxide (D50=8.94μm), and 0.05kg of RP-90 into the reactor, and mix well. Continue to add 30.0kg of carbon disulfide, and slowly add 30.0Kg of dimethylamine aqueous solution (40%); repeat this way for a total of three times until the addition is complete. Gradually raise the temperature and react to weak reflux, and the reaction ends in 3 hours. separate. The white crystal obtained is zinc dimethyl dithioaminocarboxylate. The dry product has a yield of 99.0% based on amine and a purity of 99.5%.

Embodiment 3

[0040] At room temperature, to 1m 3 Add 400kg of water, 32.5kg of ground industrial zinc oxide (D90=2.8μm), and 2.2kg of FMES into the reactor, and mix well. Continue to add 120.0kg of carbon disulfide, and slowly add 90.0Kg of dimethylamine aqueous solution (40%). Gradually raise the temperature and react to weak reflux, and the reaction ends in 6 hours. separate. The white crystal obtained is zinc dimethyl dithioaminocarboxylate. The dry product has a yield of 98.6% based on amine and a purity of 99.0%.

technical field

[0001] The invention relates to the preparation technology of fine chemicals, in particular to a method for preparing crystalline thioaminocarboxylates from secondary amines. Background technique

[0002] Thioaminocarboxylates are a class of fine chemicals that are widely used. The global annual demand is more than 50,000 tons. They are mainly used as rubber vulcanization accelerators, polymer materials and petroleum polymerization inhibitors, lubricating oil anti-wear additives, and pesticides. Wait. In specific chemical reactions, it is also used as a synergistic additive and a polymerization terminator. It is also reported to be used in the formulation of zinc-containing precursor solutions for multi-element alloy quantum dots.

[0003] The disclosed preparation technology of this type of compound includes two-step alkali method and one-step method. The two-step alkali method is adopted by most production enterprises because of its high yield and mature t...

Examples

Embodiment 1

[0036] At room temperature, to 1m 3 Add 400kg of water, 34kg of nanometer zinc oxide (average particle size of electron microscope is 57nm), 0.68kg of RP-90 into the reactor, and mix well. Continue to add 32.5kg of carbon disulfide, and slowly add 45.0Kg of dimethylamine aqueous solution (40%); after the addition, add 32.5kg of carbon disulfide again, and add dropwise 45.0Kg of dimethylamine aqueous solution (40%). Gradually raise the temperature and react to weak reflux, and the reaction ends in 5.5 hours. separate. Obtaining white crystals is zinc dimethyl dithioaminocarboxylate, and the product is finely divided crystals, and its crystal form is shown in the attached figure 1 . The dry product has a yield of 99.3% based on amine and a purity of 99.3%. The ammonia nitrogen in the mother liquor is 17mg / L, and the chemical oxygen demand is 180mg / L.

Embodiment 2

[0038] At room temperature, to 1m 3 Add 400kg of water, 43.0kg of zinc hydroxide (D50=8.94μm), and 0.05kg of RP-90 into the reactor, and mix well. Continue to add 30.0kg of carbon disulfide, and slowly add 30.0Kg of dimethylamine aqueous solution (40%); repeat this way for a total of three times until the addition is complete. Gradually raise the temperature and react to weak reflux, and the reaction ends in 3 hours. separate. The white crystal obtained is zinc dimethyl dithioaminocarboxylate. The dry product has a yield of 99.0% based on amine and a purity of 99.5%.

Embodiment 3

[0040] At room temperature, to 1m 3 Add 400kg of water, 32.5kg of ground industrial zinc oxide (D90=2.8μm), and 2.2kg of FMES into the reactor, and mix well. Continue to add 120.0kg of carbon disulfide, and slowly add 90.0Kg of dimethylamine aqueous solution (40%). Gradually raise the temperature and react to weak reflux, and the reaction ends in 6 hours. separate. The white crystal obtained is zinc dimethyl dithioaminocarboxylate. The dry product has a yield of 98.6% based on amine and a purity of 99.0%.

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