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SiO2–SO3H, with a surface area of 115 m2/g and pore volume of 0.38 cm3g−1, and 1.32 mmol H+/g was used as a 20% w/w catalyst for the preparation of methyl salicylate (wintergreen oil or MS) from acetylsalicylic acid (ASA). A 94% conversion was achieved in a microwave reactor over 40 min at 120 °C in MeOH. The resulting crude product was purified by flash chromatography. The catalyst could be reused three times. [ABSTRACT FROM AUTHOR]

This review is a survey of S-methylation of sulfur-containing organic substrates. S-methylation, being a part of S-C making bond reactions such as alkylation, arylation, alkenylation, and alkynylation, could be viewed as a test of chemical reactivity of S-bearing molecules. The sensing tools for this test are a myriad of methylating agents including common and uncommon ones: methyl halides, namely methyl iodide, dimethyl carbonate, diazomethane, methyl-containing peroxides, methyl acetates, Meerwein's reagent, methyl sulfonates, dimethylzinc. Unlike, O-, N-, and C-methylations, S-methylation mostly invoked the use of a base under mild conditions, and seldom the use of solid catalysts such as zeolites or transition metal complexes coupled with special ligands. Efforts have been exerted toward the use of water, ionic liquids, microwave assistance, phase transfer catalysis (PTC), and sonication condition in experimental protocols to achieve a smooth Smethylation. In several studied cases, the S-methylation ended up with S-methyl products with high yields and selectivity. [ABSTRACT FROM AUTHOR]

Abstract: A photoinduced N‐methylation and N‐sulfonylation of azobenzenes with dimethyl sulfoxide (DMSO) was developed in the absence of an external photosensitizer under mild conditions. The reactions underwent smoothly to generate the corresponding products in high yields through a radical addition using the starting material azobenzene as a photosensitizer. This strategy features simple operation, easily available starting materials and DMSO acting as both methylating and sulfonylating agent. [ABSTRACT FROM AUTHOR]