Thiol and disulphide derivatives of cellulose

The acid catalyzed etherification of cellulose with 1-chloro-2,3-epoxypropane yielded 3-chloro-2-hydroxypropylcellulose (SCl ≤ 0.67); the latter, by a known sequence of reactions through the thiosulphate derivative and after its reduction, gave 2-hydroxy-3-mercaptopropylcellulose (up to 0.43 mmol SH/g). Mercaptodeoxycellulose (up to 0.53 mmol SH/g) was prepared from the less reactive chlorodeoxycellulose by an analogous sequence of reactions. Bead mercaptodeoxycellulose is more advantageous obtained by using tosylate of bead cellulose; this procedure is also more advantageous than the preparation of bead 2-hydroxy-3-mercaptopropylcellulose. Disulphide derivatives of cellulose were prepard (a) by a quantitative reaction of thiol derivatives with 2,2'-dipyridyl disulphide and (b) by a reversible crosslinking of cellulose or carboxymethylcellulose with bifunctional disulphides. Disulphide derivatives of cellulose prepared by procedure (b) give after reduction thiol derivatives (up to 0.185 mmol SH/g), and further by employing procedure (a) yield 2-pyridyl disulphide derivatives.