Beilstein J. Org. Chem.2016,12, 2503–2510, doi:10.3762/bjoc.12.245
latter compounds were also transformed to sydnone-indolizines connected through a keto group at the C-4 position by refluxing them in 1,2-epoxybutane with an activated alkyne. The structures of the new compounds were assigned by FTIR, NMR spectroscopy and X-ray analysis.
Keywords: biheteroaryl