A novel class of compounds: synthesis of 5,5 '-carbonyl-bis(5,6-dihydro-4H-furo- and thieno-[2,3-c]pyrrol-4-ones)

We hereby report the first synthesis of novel class of compounds, 5,5'-carbonyl-bis(5,6-dihydro-4H-thieno- and furo-[2,3-c]pyrrol-4-one starting from methyl 2-(2-methoxy-2-oxoethyl) thiophene- and furan-3-carboxylate, respectively. The ester functionalities connected to methylene group were regiospecifically converted to the desired monoacyl azides. Curtius rearrangement of acyl azides followed by hydrolysis of the formed isocyanates gave the symmetrical urea derivatives. Cyclization of the ester groups provided the target compounds. (C) 2011 Elsevier Ltd. All rights reserved.