Wednesday, November 4, 2009
Ballroom A+B (Camino Real Hotel)
Disulfide bond formation has important applications in peptide syntheses, protein stabilization, bioactive molecules and drug delivery. Gondi and co-workers were the first to report the synthesis of trityl disulfide from triphenyl methyl thiol (trityl thiol) using nanophase manganese (VII) oxide coated clay (NM7O-coated clay) but the yield was 60%. Therefore, the objective of our research is to synthesize 100% trityl disulfide, so as to avoid cumbersome separation of the mixed products using less concentration of trityl thiol. Three different processes were researched, i.e., Parr bomb, microwave and a traditional method of heating the reactants in an oil bath at 40°C for three hrs. Microwave and Parr bomb methods were investigated to determine if pressure was one of the factors in enhancing the yield, and determine the ease of manufacturing in an industrial scale. This study indicated that this is a surface based reaction; thus, it is critical that the starting material (trityl thiol) and NM7O-coated clay has a good contact for better yield. Furthermore, the NM7O-coated clay catalyst was also tested to determine the number of times the catalyst could be reused. The use of less concentration of starting material gave 100% yield indicating the avoidance of tedious separation process. Moreover, the NM7O-coated clay is a good catalyst in that it can be used multiple times without decreasing the product yield showing the possibility of generating lesser quantity of spent catalyst. The use of NM7O-coated clay for disulfide preparation has manufacturing cost advantages.