Condensation reactions of some α-aminodiazines with pyruvaldehyde dimethyl acetal

Abstract

The condensation of 3-amino-4-methylaminopyridazine with pyruvaldehyde dimethyl acetal in methanolic hydrogen chloride has been shown (by X-ray analysis) to give 3-methoxy-2-methyl-8-methylaminoimidazo[1,2-b]pyridazine. The crystals are triclinic, space group P1, with a 8.090(1),b 11.357(2), c l1.618 (2) Å, α 88.81(2), β 70.27(2), γ 89.47(2)º, Z 4. The structure was refined to an R factor (on F) of 0.050 by full-matrix least-squares techniques. Similar reactions were observed with other 3-aminopyridazines, 2-aminopyrazine and 2-aminopyrimidine.