Nucleophilic substitution in nitro- and bromobenzo-1,2,3,4-tetrazine 1,3-dioxides (BTDOs) was studied. In most cases, the bromo and nitro groups are replaced by methylamino, dimethylamino, azido, and methoxy groups without opening of the tetrazine ring. It was illustrated with the reactions of dibromo-BTDOs with sodium methoxide that the reactivity of positions 5 to 8 in their benzene ring as regards nucleophilic substitution changes in the following order: 6 > 8 > 7 > 5. The structures of the BTDOs obtained were confirmed by H-1, C-13, and N-14 NMR data.
作者:O. Yu. Smirnov、A. M. Churakov、Yu. A. Strelenko、S. L. Ioffe、V. A. Tartakovsky
DOI:10.1023/a:1021344300420
日期:——
Benzo-1,2,3,4-tetrazine 1,3-dioxide (BTDO) and its derivatives were nitrated with HNO3/H2SO4 or HNO3/oleum and brominated with dibromoisocyanuric acid in CF3CO2H/H2SO4 (5 : 1) or H2SO4. The reactivity of positions in the benzene ring of this heterocyclic system as regards electrophilic substitution was found to change in the following order: 5 approximate to 7 > 8 > 6. Mono- and dinitro-BTDOs and mono- and polybromo-BTDOs were synthesized. Their structures were confirmed by H-1, C-13, and N-14 NMR spectra.