Synthesis and characterization of hydroxypropyl cellulose-p-aminobenzoic acid ester conjugate

Kashif-ur-Rehman Khan and Chit

Abstract

Hydroxypropyl cellulose (HPC) was modified to contain chloroacetate groups by the reaction of HPC with chloroacetyl chloride in dried dichloromethane by using pyridine as a catalyst. The coupling of para-aminobenzoic acid (PABA) to HPC functionalized with chloroacetate groups was carried out in a homogenous reaction between chloroacetylated HPC and sodium salt of PABA in dimethylsulfoxide (DMSO). The structures of chloroacetylated HPC and HPC-PABA conjugates were well characterized by FT-IR and 1H-NMR techniques. The degree of substitution (DS) per anhydroglucose unit (AUG) of chloroacetylated HPC and HPC-PABA ester conjugate was calculated by using integrated area from1H-NMR spectra. Synthesis and structural characterizations of HPC-PABA ester conjugate was successfully carried out and this strategy will contribute to the development of a potential macromolecular carrier for biomedical and pharmaceutical applications.