PREPARATION OF CHITIN-P-TOLUENESULFONATE AND DEOXY(THIOCYANATO) CHITIN

Chitin-p-toluenesulfonate(tosyl-chitin) was prepared homogeneously in lithium chloride-N,N-dimethylacetamide (LiCl/DMAc). In this solvent sy stem, the side reaction of O-acetylation often occurred by solvolysis of p-toluenesulfonyl(tosyl) chloride. The utilization of strong base e ither triethylamine or 4-dimethylaminopyridine, leads to highly tosyla ted chitin, with minimal incorporation of an O-acetyl group. Similar r esults were found in the substitution of N-methylpyrroridone (NMP) for DMAc. Chitin-4(methylamino)butylate was obtained with a pyridine cata lyst. The degree of tosylation increased with increasing amount of tos yl chloride and became constant above 1. Tosyl-chitin obtained at high reaction temperature was highly chlorinated. The tosyl-chitin with hi gh degree of substitution was readily soluble in various polar organic solvents such as dimethylsulfoxide (DMSO) and N,N-dimethylformamide ( DMF). By X-ray analysis, it was observed that the crystallinity of tos yl-chitin became low as the reaction proceeded. Treating tosyl-chitin with potassium thiocyanate in DMSO produced deoxy(thiocyanato)chitin.