Preparation method of thiadiazole derivative

Abstract

The invention discloses a preparation method of a thiadiazole derivative. The method comprises the following steps: adding an aliphatic amine substance into a formaldehyde solution of DMTD dropwise,and then carrying out reaction at 60-100DEG C for 2-5h; then raising the reaction temperature to 10-50DEG C, and carrying out reaction for 2-5h again; and after the reaction is finished, conducting reduced pressure distillation, and performing filtering to obtain the thiadiazole derivative. The preparation method disclosed by the invention can be used for safely and efficiently synthesizing the dimercaptothiadiazole derivative, and the product is easy to purify and clear in appearance; when specific raw materials are used, the oil solubility of the product is good; the product obtained by theinvention can be used as a metal deactivator, and shows a good copper corrosion inhibition effect in a copper corrosion experiment.

Description

technical field [0001] The invention relates to the technical field of lubricating oil additives, in particular to a preparation method of thiadiazole derivatives. Background technique [0002] Thiadiazole derivatives have good ion complexing and adsorption capabilities for copper and other non-ferrous metals, passivate metal surfaces and inhibit metal corrosion, and can be used as various industrial lubricants, engine lubricants, gear oils, etc. The metal deactivator can also be used as an anti-wear agent; due to the excellent metal complexation of thiadiazole derivatives, when used in combination with other antioxidants, it shows good synergistic antioxidant properties. Thiadiazole derivatives are also widely used in the United States, Europe and other countries and regions. All large multinational lubricating oil companies also have this type of metal deactivator and anti-wear agent. These products have been widely praised in the lubrication industry. There are also many...

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Problems solved by technology

[0003] There are many synthetic methods for dimercaptothiadiazole derivatives. When using 2,5 dimercapto-1,3,4 thiadiazole (DMTD) as the starting material to prepare such derivatives, hydrogen peroxide is usually used as a coupling agent. Mercaptan is used as the precursor of alkylation; hydrogen peroxide has high requirements on the operation process and equipment, and the process has safety risks; mercaptan has a strong stench, which causes great environmental pressure on production

[0004] US3087932 discloses a preparation method of thiadiazole derivatives. This patent uses a water-soluble solvent system to prepare thiadiazole derivatives by reacting dimercaptothiadiazole, mercaptan and hydrogen peroxide under milder conditions; however, there is hydrogen peroxide in this method. The disadvantages of low utilization rate and low sulfur content in the product, and the patent does not determine the preferred synthetic route and synthetic conditions

[0005] CN104178246 discloses a preparation method of a mixture of thiadiazole derivatives. In this patent, a phase transfer catalyst is used. In the post-treatment, the catalyst needs to be separated with a halogen-containing reagent, which is difficult to separate and has waste water discharge problems in practical applications; at the same time , the resulting product is a mixture of thiadiazole derivatives and by-products, and the proportion of by-products can be as high as 30%

[0006] In addition, there is a literature report (the relationship between the structure and performance of metal deactivators_Zhang Jingcheng_1988), there is a disulfide bond in the molecular structure of traditional T561, which may be converted into active sulfur during use, which will aggravate the surface corrosion of copper to a certain extent

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