Preparation of bis(4-tert-butylphenyl)iodine chloride_Kain Industrial Additive

Background^[1]

Since iodonium salt is insoluble in non-polar solvents, the photopolymerization system in which it is used as a photoinitiator must use polar solvents to dissolve the monomers, such as methanol, chloroform, etc. And because its negative ions (AsF6-, SbF6-, etc.) are toxic, its application is limited to a great extent. In response to these problems, new iodonium salts have been synthesized in recent years, mainly to improve solubility in less polar solvents and reduce toxicity. For example, the curing speed of siloxane polymerization used to initiate functionalization can reach 457m/min, so [B(C6H5)4-] has a strong tendency to replace SbF6-. Bis(4-tert-butylphenyl)iodine chloride is an iodonium salt compound, and studying its synthesis is of great significance.

Preparation^[1]

Preparation of bis(4-tert-butylphenyl)iodine chloride:

The first step, preparation of p-tert-butylphenyl iodonium hydrogen sulfate: Take 15.0g potassium iodate, 30.0g acetic anhydride, and 10.0g acetic acid and place them in the reaction bottle. Control the system temperature in an ice-salt bath – 5℃~-10℃, slowly add 14.0g of concentrated sulfuric acid dropwise during stirring. After the concentrated sulfuric acid is finished dripping, take 18.8g of tert-butylbenzene and slowly add it dropwise into the reaction system using a constant pressure funnel. Continue stirring the reaction for 24 hours, then slowly add 50 mL of deionized water dropwise, extract the solution with benzene 2 to 3 times, separate the aqueous layer, combine the benzene layer and wash it once with water, combine the aqueous layers to obtain p-tert-butylphenyl iodonium hydrogen sulfate Aqueous solution of salt.

Second step, preparation of p-tert-butylphenyliodonium hydrochloride: Dissolve 8.2g sodium chloride in water, and slowly pour it into the above-mentioned p-tert-butylphenyliodonium hydrogen sulfate aqueous solution. Stir and solid will precipitate. After suction filtration, drying and weighing, 20.6g of white bis(4-tert-butylphenyl)iodine chloride was obtained, with a yield of 68.7%.

Main reference materials

[1]CN201110129195.6 Preparation method of symmetric aryl iodonium hydrochloride