Yield:6653-91-4 750 mg

Reaction Conditions:

with hydrazine hydrate for 1 h;Reflux;

Steps:

4.1 First step: imidazo[1,2-b]pyridazine-6-yl-oxime

6-Chloramizolo[1,2-b]pyridazine (1 g, 6.5 mmol) was dissolved in hydrazine hydrate (7 mL) and heated to reflux for 1 h.After the TLC detection reaction was completed, it was cooled to room temperature, and a solid was precipitated, which was filtered, washed with a small amount of water, dried and then recrystallized from ethanol.A white solid was obtained, 750 mg.

References:

CN104341425,2018,B Location in patent:Paragraph 0150; 0152; 0153; 0154