4,4'-Dimethylbenzene sulfoxide (DMSO) is a sulfoxide compound. Representative marketed drugs containing a sulfoxide skeleton include esomeprazole (A. Aktiebolag, US5877192A, 1998), used to treat gastrointestinal disorders, and modafinil (LLLafon, US4927855A, 1990), used clinically to treat narcolepsy and anorexia. Due to their structural diversity and significant biological functions, the synthesis of sulfoxides has attracted widespread attention from organic synthetic chemists and pharmacologists. Furthermore, sulfoxide compounds possess important biological activities; by modifying their structure, their pharmacological activity can be enhanced, such as anti-ulcer, antiviral, anti-HIV-1, and antitumor effects. In the pesticide field, sulfoxide compounds offer advantages such as low dosage and low pollution as fungicides and herbicides. Sulfoxides, containing semi-polar groups, are neutral, soft-base extractants with a special affinity for noble metals in soft acids, resulting in high extraction rates and good selectivity. Furthermore, sulfoxides are important components of many natural products and pharmaceutical intermediates. Therefore, developing efficient and rapid methods for synthesizing sulfoxides is of great significance and remains a hot research area.
In a 15mL reaction tube, p-methylbenzene azomethine sulfone 1b (0.6mmol), p-methylbenzenethiol 2b (0.2mmol), acetonitrile 1mL and water 1mL were added sequentially, mixed uniformly, and then stirred and reacted under the irradiation of 3W blue LED light and the temperature of the reaction was 25 degrees Celsius for 16h. The reaction was detected by TLC until the completion of the reaction, and then ethyl acetate was added to the extract, 3mL each time, extracted 3 times, and the extracts were combined and dried with anhydrous sodium sulfate, and then the extracts were dried under vacuum (0.08Mpa) and subtracted. The extract was dried with anhydrous sodium sulfate, and then the extract was concentrated in vacuum (0.08Mpa) under reduced pressure to no solvent to obtain the crude product, and then washed with the mixed eluent of petroleum ether and ethyl acetate with the volume ratio of 5:1, and rapid column chromatography on silica gel column to obtain 4,4'-dimethylbenzenesulfinone as a yellow oily solid of 32.2 mg, with 70% yield. The yield was 70%.
