Preparation of chitin butyrate by using phosphoryl mixed anhydride system.
ABSTRACT Acylation of chitin with butyric acid was performed in the presence of trifluoroacetic anhydride/phosphoric acid mediated system. The products were characterized by (1)H NMR and FT-IR spectroscopy and their solubility was tested in different organic solvents. Inclusion of butyric acid moieties into the parent molecule was confirmed from the (1)H NMR and FT-IR spectra. FT-IR analysis revealed that the degree of acid substitution (DS) of the products was in a range of 1.9-2.38, which increased with increasing the amounts of butyric acid added to the reaction system. Degree of N-deacetylation (DD) of the products, as determined by (1)H NMR was between 54.2% and 65.6%. The products with DS >2.0 were soluble in dimethyl sulfoxide, N,N-dimethylformamide, tetrahydrofuran, methanol, acetone, chloroform, and acetic acid.
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ABSTRACT: Direct benzoylation of the two hydroxyl groups on chitosan was achieved using a phosphoryl mixed anhydride system, derived from trifluoroacetic anhydride (TFAA), benzoic acids (BAs), and phosphoric acid (PA). The reaction is operated as a one pot process under mild conditions that does not require neither an inert atmosphere nor dry solvents. The structures of the synthesized compounds were confirmed by NMR and IR spectroscopy. Solubility tests on the products revealed that they were soluble in organic solvents such as N,N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), and acetone. In the meantime, a morphological study by scanning electron microscopy (SEM) evidently indicated that the chitosan benzoates underwent significant structural changes after the benzoylation.Molecules 01/2012; 17(2):2231-9. · 2.43 Impact Factor