Routes to novel mono- and bis-tetrazole compounds: synthesis, spectroscopic and structural characterization

Relatively easy-to-run synthetic routes to new mono-[1-(2-(4,5-dihydro-1H-imidazol-1-yl)ethyl)-1H-tetrazole (1) and 3-(2-(1H-tetrazol-1-yl)ethyl)oxazolidin-2-one (13)], and bis-tetrazole [N,N-bis(2-(1H-tetrazol-1-yl)ethyl)-formamide (2), bis(2-(1H-tetrazol-1-yl)ethyl)amine (3), N-(2-(1H-tetrazol-1-yl)ethyl)-N-(2-(2-(1H-tetrazol-1-yl)-ethylamino)ethyl)formamide (5), N-1,N-2-bis(2-(1H-tetrazol-1-yl)ethyl)ethane-1,2-diamine (6), N,N'-(2,2'-azanediylbis(ethane-2,1-diyl))bis(N-(2-(1H-tetrazol-1-yl)ethyl)formamide) (8) and N-1-(2-(1H-tetrazol-1-yl)ethyl)-N-2-(2-(2-(1H-tetrazol-1-yl)ethylamino)ethyl)ethane-1,2-diamine (9)] ligands have been developed. 2 (whose crystal structure is described), 3, 5, 6, 8 and 9 are of particular interest as precursors for further functionalization due to the aldehyde and secondary amine functions, while 2, 5, 8 and 13 are potential synthons for the formation of ditopic ligands for metal-organic framework construction. Unexpected instability of Boc under basic and nucleophilic conditions at high temperature followed by fragmentation of tert-butyl 2-chloroethyl(2-(2-chloroethylamino)ethyl)carbamate (14) and tert-butyl 2,2'-azanediylbis(ethane-2,1-diyl)bis(2-chloroethylcarbamate) (15) afforded 13, whose crystal structure is presented.