An efficient synthesis of carbazole-based secretory phospholipase A2 (sPLA2) inhibitors LSN433771 and LSN426891

The flexible and efficient synthesis of two structurally similar carbazole derivatives is described. This general strategy features an intramolecular palladium-mediated biaryl coupling reaction to join two aromatic domains of the target molecules. Formation of the carbazole core is accomplished via nitrene insertion. The synthesis of secretory phospholipase A2 (sPLA2) inhibitors LSN433771 (1) and LSN426891 (2) is detailed.