Preparation of chitin butyrate by using phosphoryl mixed anhydride system

TFAA-H3PO4 mediated rapid and single-step synthesis of mutual prodrugs of paracetamol and NSAIDs

“…We have previously reported that the neat reaction of phenol with carboxylic acid in presence of TFAA and 85% phosphoric acid at room temp or 50Á608C proceeds well leading to the formation of CÁO bond thereby the corresponding ester (16). This handy methodology is being utilized elegantly for the preparation of various target compounds by other research groups (17). However, to our surprise under these conditions when employed, paracetamol and NSAIDs were found to be inert as no formation of desired ester was detected.…”

Preparation and Characterization of Chitin Benzoic Acid Esters

“…Chitin benzoates were prepared as described previously [ 13 , 17 ]. In brief, trifluoroacetic anhydride (TFAA) and benzoic acid were initially combined and stirred at 40 ºC until complete dissolution.…”

“…The trifluoroacetic anhydride/phosphoric acid (TFAA/H 3 PO 4 ) reaction system is an efficient coupling agent for the direct O -acylation of phenolic hydroxy groups with free carboxylic acids [ 12 ]. This method has been employed for the preparation of a range of aryl carboxylate esters [ 12 ], and more recently for the preparation of chitin butyrate [ 13 ]. In this work, we report the TFAA/H 3 PO 4 promoted synthesis of chitin benzoates by reacting chitin with benzoic acid ( Scheme 1 , Table 1 ).…”

Chitin dipentanoate as the new technologically usable biomaterial

“…Alternative methods of chitin ester preparation include the synthesis in the presence of fatty acids in trifluoroacetic anhydrides [35] Materials Science and Engineering C 55 (2015) [50][51][52][53][54][55][56][57][58][59][60] and acylation with butyric acid in the presence of trifluoroacetic anhydride/phosphoric acid system [36].…”