3(2H)-Pyridazinone,6-(1-piperazinyl)-(9CI) synthesis

Yield:145276-53-5 65.9%

Reaction Conditions:

with acetic acid at 120; for 16 h;

Steps:

3 Preparation of 6-(Piperazin-1-yl)pyridazin-3(2H)-one 6-4

Preparation of 6-(Piperazin-1-yl)pyridazin-3(2H)-one 6-4: (1204) A solution of tert-butyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate 6-3 (2.2 g, 7.36 mmol) in acetic acid (20mL) was heated at 120 °C for 16 h. After complete consumption of Cpd-3 as evident from TLC, the volatiles were stripped off, residue partitioned between ethyl acetate and water, combined organic extracts evaporated to afford a crude residue which was purified over neutral alumina (elution with 30% methanol/DCM)to afford 6-(piperazin-1- yl)pyridazin-3(2H)-one 6-4 (871 mg, 4.83 mmol, 65.9 %) as a brown solid. LC MS: ES+ 181.1

References:

WO2017/197051,2017,A1 Location in patent:Page/Page column 300