Collect. Czech. Chem. Commun. 1994, 59, 2269-2281

Reactions of 2,4,4,6-Tetraaryl-4H-thiopyrans with Chlorine: An Unusual Reaction Route

Pavel Šebeka, Jiří Kroulíkb, Petr Sedmerac, Vladimír Havlíčekc and Josef Kuthanb

a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague 6, Czech Republic
b Department of Organic Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic
c Institute of Microbiology, Academy of Sciences of the Czech Republic, 142 20 Prague 4, Czech Republic


2,4,4,6-Tetraaryl-4H-thiopyrans Ia - Ig react smoothly with carbon disulfide solution of chlorine already at 0 °C yielding the corresponding 3,5-dichloro derivatives IIa - IIg. With longer reaction time and temperature raised to 20 °C, the 4H-thiopyrans Ia - Ie gave exclusively the trichloro derivatives IIIa - IIIe whereas If and Ig underwent a nonselective chlorination leading to multicomponent mixtures of products. Isolation of sulfoxides IVa and IVe from the chlorination of Ia and Ie (upon hydrolysis of the reaction mixture) allowed us to formulate the reaction mechanism for the formation of compounds type III. 1H, 13C NMR, and mass spectra of the prepared compounds are discussed in detail.