Synthesis and chemoselectivity of novel methylated N-benzyl chitosan derivatives with iodomethane

POLY 169

Warayuth Sajomsang, chdaly@lsu.edu1, Supawan Tantayanon, supawan.t@chula.ac.th2, William H. Daly, chdaly@lsu.edu3, and Varawut Tangpasuthadol2. (1) Department of Chemistry, Faculty of Science, Chulalongkhorn University, Phayathai Rd, Bangkok, 10330, Thailand, (2) Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Rd., Bangkok, 10330, Thailand, (3) Department of Chemistry, Louisiana State University, 712 Choppin Hall, Baton Rouge, LA 70803-1804
The one-step methylation of N-(p-N,N-dimethylaminobenzyl) chitosan and N-(4-pyridylmethyl) chitosan with iodomethane was successfully conducted to produce compounds that easily dissolved in water. The reactions were performed using iodomethane and sodium hydroxide at different concentrations in NMP at 50 °C for 12 hours. 1H-NMR spectroscopic technique was utilized for characterization, i.e., extent of substitution (ES), degree of quaternization (DQ), and degree of O-methylation (EOM). It was found that the presence of N,N-dimethylaminobenzyl and pyridylmethyl groups contributed high DQ up to 60%. However, the concentration of base is the more important factor for controlling chemoselectivity.
 

General Papers: Synthesis and Characterization
6:00 PM-8:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster

Division of Polymer Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006