Microwave-assisted synthesis of new imide-and formamide-derivatives of 2(3H)-benzoxazolinones and 2(3H)-benzothiazolinones

With the aim to obtain 2(3H)-benzoxazolinones and 2(3H)-benzothiazolinone derivatives, we synthesized new imide compounds 5a-c, 6c-d and 7a-d by treating their 6-amino precursors with succinic, maleic or phthalic anhydride. The microwave (MW)-assisted reaction provided them more efficiently than through the corresponding isolated amic acids. The same nucleophile reagents were used in a MW-assisted formylation to obtain new formamide products 8-11, that were detected as cis/trans forms by NMR analysis. The ratio was in favor of the cis isomer and affected by the solvent, as also supported by DFT calculations