Application of Poly(N, N′- dibromo-N-ethyl-naphthyl-2,7-disulfonamide) for the Regioselective Synthesis of New 3-Sulfenyl Indole Derivatives

Electron-rich aza-aromatic compounds such as indoles is structures of particular interest and importancein organic chemistry. A useful procedure for the preparation of new 3-sulfenyl indole derivatives using S-alkyl or S-arylthiophthalimides as sulfenylating agents and poly(N, N′-dibromo-N-ethyl-naphthyl-2,7-disulfonamide) as novel catalyst is described. The method represents an efficient preparation ofsulfenyl aza-aromatics, which are useful intermediates forimportant organic transformations, due to the great importanceof functionalized indoles among natural compoundsand pharmaceutical products.3-Arylthioindole apply as a block of compounds for the treatment of diseases. The direct 3-arylthiolation of 2-substituted indoles using poly(N, N′-dibromo-N-ethyl-naphthyl-2,7-disulfonamide) in CH2 Cl2 with a wide variety of indole deraivatives has been accomplished.This method is effective even with 2-unsubstituted indoles.Simple methodology, easy workup procedure, regioselectivity and reusability of the catalyst are some advantages of this work.The reaction occurred under mild conditions,and the products were obtained in goodyields. The catalyst was recovered after completion of the reaction and re-used with minimum loss of activity over five cycles.