A facile design and efficient synthesis of schiff's bases of tetrazolo [1,5-a] quinoxalines as potential anti-inflammatory and anti-microbial agents
By Umarani Natarajan, Ilango Kaliappan, Narendra Kumar Singh
A novel synthetic methodology of schiff's bases incorporating tetrazolo quinoxalines is described. O-Phenylene diamine on condensation with oxalic acid using Phillip’s procedure yielded the corresponding quinoxaline-2,3-dione 1. The latter on chlorination afforded 2,3-dichloroquinoxaline 2. This on hydrazinolysis gave the known 3-chloro-2-hydrazino quinoxaline 3, which further undergoes cyclisation with sodium azide to obtain 2-hydrazino tetrazolo [1,5-a]quinoxaline 4. Finally this synthesized scaffold made to react with different aromatic aldehydes furnished the formation of 1-substituted hydrazino tetrazolo [1, 5-a] quinoxalines 5a-j. The structures of all these title compounds were confirmed by their IR, 1HNMR, and Mass spectral analysis. All the newly synthesized heterocycles have been screened for their in vitro antimicrobial and anti-inflammatory activities. Few of them exhibited promising activity. The ambient conditions, excellent product yields and easy work up procedures make this synthetic strategy a better protocol for the synthesis of newer schiff's derivatives.
Keywords : Tetrazolo quinoxalines, scaffold, spectral studies, synthetic strategy