Synthesis of a novel pyrrole oxazole analogue of the insecticide pirate

The pyrrole oxazole 4 is a novel analogue of the broad-spectrum insecticide and miticide pirate 2. The expedient synthesis of pyrrole oxazole 4 in six steps from pyrrole is reported using a synthetic route that could have potential for the solution-phase combinatorial synthesis of analogues. Preliminary biological evaluation of the protected pyrrole oxazole 4 (LD₅₀ 1.13 μg mL^–1) and the deprotected pyrrole oxazole 5 (LD₅₀ 1.06 μg mL^–1) for potential cytotoxicity was carried out.