Benzothianthrene oxide

Serge L. Beaucage Food and Drug Administration, Bethesda, MD, USA 

Alternate Name thianthrene monosulfoxide, thianthrene-5-oxide, thianthrene monoxide, Adam probe. 

Solubility very soluble in chloroform and acetone, slightly less soluble in glacial acetic acid and benzene, slightly soluble in methanol and ethanol, very slightly soluble in petroleum ether and diethyl ether. Very soluble in boiling water. 

Purity title compound forms long off-white needles when recrystallized from methanol, ethanol, or benzene. 

The procedure described was extended to the synthesis of other C2-amido glycosides. Primary amides such as benzamide, 2-benzyloxyacetamide, and pent-4-enamide were used in place of 7V-trimethylacetamide to form the corresponding imidates which 

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Interpretation of the stereo- and chemoselectivity of oxidation reactions using thianthrene oxide must consider its low barrier to ring-inversion, steric effects, and the role that solvents may play in the product distribution. All of these possibilities could influence the Xso value of oxidants. Specifically, mechanistic consideration of electrophilic oxidation of thianthrene oxide in the presence of protic solvents or acid leads to diminished yields of SSO2. Despite aU of these concerns, benzothianthrene oxide is still considered a reliable probe for the electronic character of oxidants. 

Related Reagents. 1-Benzenesulfinyl Piperidine Methoxy-phenyl Benzenethiosulfinate Benzothianthrene Oxide W Iodo-succinitnide Dimethyl(methylthio)sulfonium Tetrafluoroborate. 

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