Alkylation of some substituted tetrazolo[1,5-α]pyridines studied by 1H, 13C, 15N NMR and ab initio molecular orbital calculations

H-1, C-13 and N-15 NMR parameters and ab initio molecular orbital calculations were used to characterise some alkylated and arylated tetrazolo[1,5-a]pyridines. We have found that tetrazolo[1,5-a]pyridine (1) and its substituted derivatives undergo alkylation and this reaction results in mixtures of the N1- and N2-alkyl compounds (a, c and b, d) in different ratios, depending on the position and nature of substituents. NMR spectral parameters for N3-aryltetrazolo[1,5-a]pyridine (e) obtained by cyclization of 2-pyridyl-aryltriazenes are also presented. (C) 1999 Elsevier Science B.V. All rights reserved.