Convenient synthesis and in vitro activity of oxalyl bis(benzenesulfonylhydrazides) and related compounds

Symmetrical oxalyl bis(benzenesulfonylhydrazides) [ObBSH] were conveniently prepared by reacting various sulfonyl hydrazides with oxalyl chloride in refluxing tetrahydrofuran (or toluene). The crude products were obtained practically as virtually pure compounds in high yields. While synthetic access to oxalyl bis(benzenesulfonylhydrazides) has been described in the literature, this report delineates a facile protocol for preparing such type of compounds under relatively mild conditions from inexpensive, commercially available, and chemically stable reagents. Non-symmetrical oxalyl ObBSH were also obtained via modified one-pot, two-step synthetic protocol. However, those products required purification due to contaminations arising from the concurrent formation of the symmetrical counterparts. These newly synthesized molecules were screened in an acetylcholinesterase in vitro enzymatic assay. Several compounds showed inhibitory potency in low micromolar range, which aligns with results reported previously for similar compounds. Overall, the synthetic protocols presented herein revisit the preparation of oxalyl bis(benzenesulfonylhydrazides), which have been previously characterized as blowing agents possessing potential for commercial applications and might be also further explored in search of bioactive properties.