2- Methylthio -2-phenyl-l,3-dithiane

C. 3-(2-Phenyl-l,S-dithian-2-yl)indole [IH-Indole, 3-(2-phenyl-l,S- dithian-2-yiy. A solution of 24.2 g. (0.10 mole) of 2-methylthio-2-phenyl-l,3-dithiane and 6.86 g. (0.050 mole) of indole [li/-Indole] in 600 ml. of chloroform is placed in a 2-1., three-necked hask fitted with a mechanical stirrer and a 100-ml., pressure-equalizing dropping funnel. The reaction mixture is stirred vigorously, and a solution of 25 ml. (about 0.2 mole) of boron trifluoride etherate [Borane, trifluoro, compd. with l,T-oxybis[ethane](l 1)] (Note 6) in 50 ml. of chloroform is added over 10 minutes. An orange-brown, resinous precipitate forms as the slightly exothermic reaction proceeds. After a further 10 minutes of stirring, a solution of 5.86 g. (0.050 mole) of indole in 60 ml. of chloroform is added in one portion. 

Butyllithium in hexane injected through a septum cap at -78° under Ng during 25 min. into a soln. of 2-phenyl-l,3-dithiane in tetrahydrofuran, stirred 2 hrs. at the same temp., dimethyl disulfide injected during 10 min., allowed to warm to 25°, then poured into dil. HCl crude 2-methylthio-2-phenyl-l,3-dithiane (Y 94.5%) refluxed 4.5 hrs. under N2 with 95%-ethanol, HgClg, and HgO ethyl benzoate (Y 92.4%). F. e. and process, also carboxylic acids, s. R. A. Ellison, W. D. Woessner, and C. C. Williams, J. Org. Chem. 37, 2757 (1972). 

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