Method for synthesizing pentaerythritol tetra (3-lauryl thiopropionate) by one-pot method

Abstract

The invention provides a method for synthesizing pentaerythritol tetra (3-lauryl thiopropionate) by a one-pot process. The method comprises the following steps: adding a reaction solvent into a reaction container, then sequentially adding pentaerythritol, acrylic acid, triethylamine and catalytic equivalent strong base, heating to 55 DEG C, slowly dropwise adding dodecanethiol, keeping the temperature for 2 hours, slowly dropwise adding a reaction solution in which triphosgene is dissolved, and carrying out heat preservation and stirring for 2 hours after dropwise adding is completed; and after the reaction is finished, washing with water, removing the solvent, and crystallizing and separating to obtain the product. According to the invention, the method has the characteristics of low raw material cost, mild reaction conditions, high reaction speed, simplicity in operation, less pollution and environmental friendliness; and compared with the high-temperature reaction conditions required for synthesizing pentaerythritol tetra (3-lauryl thiopropionate) by a transesterification method or esterification method, the energy consumption is effectively reduced, the production time is shortened, the production efficiency is improved, and the method is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of chemical synthesis methods; in particular, it relates to a method for synthesizing pentaerythritol tetrakis (3-lauryl thiopropionate) in one pot. Background technique [0002] Pentaerythritol tetrakis (3-lauryl thiopropionate) is a kind of organic sulfur antioxidant with high efficiency, low toxicity, odorless, non-polluting, non-volatile, non-discoloration, heat resistance, aging resistance, etc., specially developed for For polyolefin and engineering plastic products, it is especially recommended for the fields with strict requirements on high temperature and long-term aging performance. When pentaerythritol tetrakis (3-lauryl thiopropionate) is used in conjunction with hindered phenolic primary antioxidants, it is relatively Compared with traditional thioether antioxidants, such as DLTP and DSTP, it exhibits superior stability. [0003] The synthesis and development of sulfur-containing antioxidant pe...

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Problems solved by technology

[0004] US4774355 discloses a kind of amide alcoholysis synthetic method, at first take 1-dodecyl mercaptan and acrylamide as raw material synthesis 3-dodecyl thiopropionate methyl ester, then obtain pentaerythritol tetrakis (3- n-dodecyl thiopropionate), but the reaction time of this method is as long as 24 hours, and the yield is not high and only 75%

[0005] US5093517 discloses a kind of transesterification synthesis method: at first take 1-dodecyl mercaptan and methyl acrylate as raw materials to synthesize 3-dodecyl thiopropionate methyl ester, then obtain pentaerythritol tetrakis (3- N-dodecyl thiopropionate), the yield is as high as 86%, but the tin-containing catalyst used cannot be completely removed, which has adverse effects on products and the environment, and the reaction temperature is high, and the consumption time is long, so it is more difficult to industrialize

[0006] US5057622 discloses a direct esterification method: this method is similar to the transesterification synthesis method disclosed in US5093517, and methyl acrylate is replaced by acrylic acid. Although the yield of this method is as high as 97.6%, this method will produce a large amount of waste concentrated brine. Difficulty, high cost, and the need for esterification under high temperature conditions, high energy consumption, long reaction time, difficult to industrialize

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