m-Chloroperbenzoic acid → 2-(4-Hydroxybenzoyl)-3-phenylbenzothiophene-1-oxide

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Reaction Steps

The product from Example 3 (5.0 g.; 0.0151 mole) and 2.8 g. of m-chloroperbenzoic acid were dissolved together in chloroform. The mixture was allowed to stand at room temperature for about 3 days. The solution then was washed twice with aqueous sodium bicarbonate solution, then with water, and was dried over magnesium sulfate. The solution then was concentrated to dryness. Thin-layer chromatography (TLC) run on the crude product revealed the presence of the starting material, some sulfone, and the desired product. The mixture was slurried in hot benzene, allowed to cool, and filtered to obtain 2.6 g. of a material having m.p. 140°-145° C. TLC on this product indicated some sulfone was still present. The solid was slurried in benzene, warmed, and filtered while hot. The collected solid then was slurried in benzene containing a small amount of ethanol, heated, and allowed to cool. The title compound (1.3 g.) crystallized out and was collected by filtration. TLC of this product indicated the presence only of traces of the sulfone contaminant. The melting point of the product was 215° C. The product was dried in vacuo at 120° C. overnight to further remove any solvent which might be present.

Provenance & Evidence