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

Abstract

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), N1,N2-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 N1-(2-(1H-tetrazol-1-yl)ethyl)-N2-(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.