A study of the reaction of chlorosulfonyl isocyanate with polyisoprenes

Abstract

The human body, though unequalled in design and function, is prone to the effects of aging, disease, and accidents. In these cases, the intervention of science is necessary to preserve the quality of life, or even life itself. When one is considering artificial implants, the most important factor that determines biocompatibility is blood compatibility. In general, the more blood compatible an implant is, the more biocompatible that implant is. In this paper the reaction of chlorosulfonyl isocyanate (CL-So2-N=C=O) with various compounds, especially polyisoprenes, will be examined. The addition products (substituted beta lactams) can then be hydrolyzed to give compounds that have many structural features in common with heparin, e.g., sulfamate and carboxylate groups, as shown by Graf (1,2). Heparin, nature's own anticoagulant, is the perfect compound to model. Using this technique, it should be possible to obtain a more biocompatible surface (3). Sederel, et al (4), have shown that this methodology can be used to develop an artificial anticoagulant with activities near that of natural products. The resulting compound has many of the same functionalities as heparin, primarily the sulfamate and carboxylate groups, and shows excellent blood compatibility. They were also able to show that as the sulfamate content increases, so does the anticoagulant activity of the resulting compounds. The work above suggests the methodology of the current paper, carrying out the reaction of chlorosulfonyl isocyanate with polyisoprenes and varying the degree of substitution in order to obtain a polymeric system with the maximum biocompatibility and the desired polymeric chain flexibility. This system could be used to synthesize implants with the best possible characteristics. The present work also involved the improvement of the initial yields and general debugging of the experimental technique to give optimum yields of the desired product (3).