1,ω‐Bis(4‐amino‐1,2,4‐triazole‐5(1 H )‐thion‐3‐ylsulfanyl)alkanes: Versatile precursors for novel bis( S ‐triazolo[3,4‐ b ][1,3,4]thiadiazines) as well as novel bis(macrocyclic schiff bases)

Two synthetic routes were attempted for the synthesis of the novel bis(5,6‐dihydro‐ S ‐triazolo[3,4‐ b ]thiadiazines) 12a,b and 14 . In the first route the bis(aminotriazoles) 4a,b were reacted with the appropriate α‐haloketones or α‐haloesters to give the corresponding bis( S ‐triazolo[3,4‐ b ]thiadiazines) 11a‐d followed by reduction with NaBH 4 . In the second route, the bis(Schiff bases) 13d were reacted with the appropriate α‐haloesters in refluxing DMF containing TEA to give the target compound 14 . Cyclocondensation of 4a,b with the appropriate bis(carbonyl) ethers 15a,b in refluxing acetic acid under high dilution conditions afforded the corresponding macrocyclic Schiff bases 16a‐c . The latter underwent alkylation with the appropriate halo compounds to give the corresponding alkylated derivatives 17a‐d .