107575-06-4Relevant academic research and scientific papers
Photochemical Formation of Heteromethylenecyclopropanes, 16. - 1,4,5-Substituted Tetrazolium Salts Through Methylation of 1,5-Substituted Tetrazoles and Cycloaddition of Alkyl Azides to Nitrilium Ions
Quast, Helmut,Bieber, Lothar,Meichsner, Georg
, p. 469 - 476 (2007/10/02)
Efficient syntheses of isomerically pure 1,4,5-substituted tetrazolium salts are reported.Methylation of 1,5-substituted tetrazoles 5 affords mixtures of 1,4,5- (1) and 1,3,5-substituted tetrazolium salts 6.The ratio 1:6 depends only little on the reaction conditions as well as on the methylating agents.The isomerically pure tetrazolium salts 1a-e, g, j, k and 6j, k are isolated by fractionating crystallizations. tert-Butylation of 5a, c using tert-butyl alcohol/tetrafluoroboric acid produces only the 3-tert-butyltetrazolium tetrafluoroborates 9a, c.The N-methylnitrili um tetrafluoroborates, fluorosulfonates or trifluoromethanesulfonates 7a-c and e cycloadd the alkyl azides 8a-d regioselectively to the tetrazolium salts 1a-c, e, f, h, i.Both rate and yield of the cycloaddition decrease with increasing size of the substituents.The N-tert-butylnitrilium tetrachloroferrate 7h (X=FeCl4) reacts with methyl azide (8a) yielding the hydrogen tetrachloroferrate 4a*HFeCl4 of the imidoyl chloride 4a.
