Synthesis of N-substituted isocyanocarboxamides with antimicrobial activity

The Ugi four-component condensation between isocyanides 1, cycloketones 2, and ammonium formate affords N-substituted formylaminocarboxamides 3 which are dehydrated with POCl3/NEt3 to give the title compounds 4. The structure of the compounds 3 and 4 was confirmed by spectral data and elemental analyses. In vitro tests of antibacterial activity showed that compounds 4 are ineffective against E. coli and fairly active against K. pneumoniae, B. subtilis and S. aureus. A very good antimicotic activity was shown against C. albicans.