METHOD OF PRODUCING 4-AMINOPYRIDAZINES Russian patent published in 2021 - IPC C07D237/20 C07D403/12 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing a pyridazinamine compound of formula V or a salt thereof, a tautomer or an N-oxide. Method includes a step of reacting (a) a dichloropyridazinamine compound of formula IVa or a salt thereof, a tautomer or N-oxide, or (b) a dichloropyridazinamine compound of formula IVb or a salt thereof, a tautomer or N-oxide, or (c) mixture (a) and (b) with hydrogen in the presence of a hydrogenation catalyst. Method further includes a step of producing (a) a dichloropyridazinamine compound of formula IVa or a salt thereof, a tautomer or N-oxide, or (b) a dichloropyridazinamine compound of formula IVb or a salt thereof, tautomer or N-oxide, or (c) mixture (a) and (b) by a reaction involving steps of reacting a compound of formula II with POCl₃ and reacting the obtained crude reaction product with an amino compound R¹-NH₂ or a salt thereof. Formed in situ 3,4,5-trichloropyrazine is directly reacted with an amino compound to obtain desired dichloropyridazinamine compounds, stage of extraction of trichloropyrazine compound is passed and trichloropyridazine is transferred into organic phase and is directly used at the next reaction stage. In compounds of formulas IV, IVa and VR¹ is H, C₁-C₂-alkyl or C₁-C₂-alkoxy-C₁-C₂-alkyl. Invention also relates to a method of producing (a) a dichloropyridazinamine compound of formula IVa or a salt thereof, a tautomer or N-oxide, or (b) a dichloropyridazinamine compound of formula IVb or a salt thereof, a tautomer or N-oxide, or (c) a mixture of (a) and (b). Method includes steps of reacting a compound of formula II with POCl₃ and reacting the obtained crude reaction product with an amino compound R¹-NH₂ or a salt thereof.

EFFECT: no need to add a base as an additional chemical; possibility of repeated use of hydrogenation catalyst without its purification, high yields of the product.

9 cl, 1 ex