FUNCTIONALIZATION OF POLYSTYRENE .3. SYNTHESIS OF POLYMERIC THIOL REAGENTS

The synthesis of polymer-bound thiol reagents, supported on macroporous 4% divinylbenzene copolymer (Amberlite XE-305), via three synthetic approaches is described: (1) Alkylation or acylation of XE-305 with 3-nitro-4-halogen-substituted benzyl chloride or benzoyl halide yielding 3-nitro-4-halobenzene-bound species, followed by substitution of the activated polymeric halogen atom with sulfur. (2) Formation of a thiol ether by a direct substitution of an active polymeric halogen by reaction with benzylthiol, followed by chlorination, thiolation, and reduction. (3) Attachment of a prepared tailor-made disulfide to aminomethyl function of a polymeric support, followed by reduction. The polymers were tested for their free-thiol content by 5,5 prime -dithiobis(2-nitrobenzoic acid) in DMF. Their thiolytic activity was investigated in the removal of 2-nitrophenylsulphenyl (Nps) group from Nps-protected amino acid.