Acid-base properties of 1,2,5-oxadiazoles. 1. Methylfurazans

The basicities of 3-methyl-4-R-furazans (R = H, CH₃, C₂H₅, n-C₃H₇, NH₂ NHAcOCH₃, I, COOH, and NO₂) were investigated by PMR spectroscopy. It is shown that they are weak bases, the protonation of which is described by the H_A acidity function. Relationships between the chemical shifts of the protons of the methyl group and the R ° constants and the p_aBH^K+ and the M ° constants of the substituents were found.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 35–37, January, 1981.