Triethylamine → 2-(4-chloro-3,5-diphenyl-1H-pyrazolo[3,4-c]pyridazin-1-yl)-N-methylacetamide

Participants

Reaction Steps

Compound 5 was synthesised from 2-(4-chloro-3,5-diphenyl-1H-pyrazolo[3,4-c]pyridazin-1-yl)acetic acid, which was synthesised following similar procedures outlined in Example 1 (Compound 37), using benzoylacetonitrile instead of 2-chlorobenzoyl acetonitrile and ethyl hydrazinoacetate hydrochloride and 1.5 equivalent of triethylamine instead of methylhydrazine in Step 1. To a suspension of 2-(4-chloro-3,5-diphenyl-1H-pyrazolo[3,4-c]pyridazin-1-yl)acetic acid (73 mg, 0.2 mmol) in CH2Cl2 (1 mL) were added 2-hydroxypyridine-N-oxide (HOPO) (22 mg, 0.2 mmol), methylamine hydrochloride (14 mg, 0.2 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDAC) (50 mg, 0.25 mmol), diisopropylethylamine (DIPEA) (90 μl, 0.2 mmol) and DMF (0.5 mL). The reaction mixture was stirred at room temperature for 90 min then concentrated in vacuo. The residue was purified by preparative HPLC yielding Compound 5 as an off-white solid (6 mg).

Provenance & Evidence