Synthesis of 3,5-Disubstituted-1,2,4-thiadiazoles via NaH-DMF-Promoted Dehydrogenative Intramolecular N-S Bond Formation.

A facile transition-metal-free synthesis of 3,5-bis(het)aryl/arylaminothiadiazoles has been reported. The overall protocol involves base-mediated tandem thioacylation of amidines with dithioesters or aryl isothiocyanates in DMF solvent and subsequent in situ intramolecular dehydrogenative N-S bond formation of thioacylamidine intermediates under an inert atmosphere. A probable mechanism involving a carbamoyl anion, generated by deprotonation of DMF, acting as a radical initiator has been suggested.

X-ray structure, hirshfeld surfaces and interaction energy studies of 2,2-diphenyl-1-oxa-3-oxonia-2-boratanaphthalene.

Single crystal XRD structure of the title compound reveals that the molecule adopt non-planar structure. The molecule is puckered with the total puckering amplitude of (Q) = 0.368(3)Å. Crystals of the title molecules are interconnected by intermolecular O-H⋯O and C-H⋯O interactions to develop 1D chains extending infinitely along the crystallographic a-axis. The intermolecular interactions were explored by Hirshfeld surfaces and their associated fingerprint graphs are obtained which revealed that the H⋯H and H⋯C pairs of inter atomic contacts were pre-dominant in the crystal packing of title compound. The energy of intermolecular interactions are computed using the accurate energy density model of B3LYP/6-31 G(d,p).