Benzothianthrene Oxide

Abstract

[2362-50-7] C12H8OS2 (MW 232.32) InChI = 1S/C12H8OS2/c13-15-11-7-3-1-5-9(11)14-10-6-2-4-8-12(10)15/h1-8H InChIKey = NYVGTLXTOJKHJN-UHFFFAOYSA-N (reagent used to activate glycals for acylamidoglycosylation and as a probe of the electronic character of oxygen transfer reagents) Alternate Name: thianthrene monosulfoxide, thianthrene-5-oxide, thianthrene monoxide, Adam probe. Physical Data: mp 142–144 °C. 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. Form Supplied in: off-white crystals. Preparative Methods: the title reagent has been prepared by the oxidation of thianthrene via numerous methods. The most often cited method is by Gilman and Swayampati,1 which is actually a modified version of the first reported synthesis by Fries and Vogt.2 In 86.4 g (0.4 mol) of thianthrene was added 1.4 L of glacial acetic acid and refluxed. To this mixture 150 mL of dilute nitric acid (40%) was added dropwise over 1.5 h. The mixture was further allowed to reflux for 15 min. The yellow solution was diluted with 5 L of ice water and the product was filtered, washed with water, and dried to yield 90.5 g (98%) of off-white crystals of benzothianthrene oxide. Another method is the oxidation of the commercially available thianthrene by m-chloroperbenzoic acid (m-CPBA).3, 4 To a solution of thianthrene (37 mmol) in CH2Cl2 at room temperature, a solution of 88% m-CPBA (50 mmol) in CH2Cl2 was slowly added. Once all of the thianthrene got dissolved, the mixture was washed with 2 L of aqueous NaHCO3, then with 1 L of H2O, dried over MgSO4, and finally concentrated under reduced pressure. The sample was then chromatographed on silica gel utilizing cyclohexane/ethyl acetate (9:1) as eluent to give thianthrene oxide in a good yield. title compound forms long off-white needles when recrystallized from methanol, ethanol, or benzene.