Chung Shan Institute of Science and Technology

Chung-Chien Chang

Shean-Jeng Jong

Chun-Hsu Lin

Ming-Te Shih

Chao-Chou Tu

Chao-chou Tu

A method and a device for purifying 1,4-bis(bromodifluoromethyl)benzene are disclosed. In order to solve the problem of hard to purify and separate 1,4-bis(bromodifluoromethyl)benzene crude products, diphenylmethane that has a higher boiling point and does not interact with 1,4-bis(bromodifluoromethyl)benzene is mixed with the 1,4-bis(bromodifluoromethyl)benzene crude products for evaporation. Afterwards, the purity of the vaporized product is detected and only that reaching an expected purity is collected to obtain high-purity 1,4-bis(bromodifluoromethyl)benzene.

Method and device for purifying 1,4-bis (bromodifluoromethyl) benzene

A method of synthesizing a high purity product of &#x3b1;,&#x3b1;,&#x3b1;',&#x3b1;&#x2032;-tetrachloro-p-xylene is disclosed. The method includes carrying out a first stage reaction of terephthaldicarboxaldehyde with a mixture of SOCland dimethylformamide (DMF) to obtain a product mixture containing &#x3b1;,&#x3b1;,&#x3b1;&#x2032;,&#x3b1;&#x2032;-tetrachloro-p-xylene as a major product and 4-dichloromethyl benzaldehyde as a side product; adding SOCland DMF to the product mixture of the first stage reaction to undergo a second stage reaction; and to a cool water adding the resulting product mixture from the second stage reaction to obtain a solid product of &#x3b1;,&#x3b1;,&#x3b1;&#x2032;,&#x3b1;&#x2032;-tetrachloro-p-xylene with a purity of 90-99 mol %.

Method for the preparation of &#x3b1;,&#x3b1;,&#x3b1;',&#x3b1;&#x2032;-tetrachloro-p-xylene with high purity

A synthesis method of &#x3b1;,&#x3b1;,&#x3b1;',&#x3b1;&#x2032;-tetrachloro-p-xylene is disclosed. The method includes reacting terephthaldicarboxaldehyde with a mixture of SOCland dimethylformamide (DMF) to obtain a product mixture containing &#x3b1;,&#x3b1;,&#x3b1;&#x2032;,&#x3b1;&#x2032;-tetrachloro-p-xylene as a major product and 4-dichloromethyl benzaldehyde as a side product, which can be separated by silica column chromatography.

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Taipei, Taiwan

Chung-Chien Chang