Triethylamine → (R)-(4-(1-chloropyrido[3,4-d]pyridazin-4-yl)-3-methylpiperazin-1-yl)(4,4-difluorocyclohexyl)methanone

Participants

Reaction Conditions

Reaction Steps

4,4-difluorocyclohexanecarboxylic acid (277 mg, 169 mmol) and bis(2-oxo-3-oxazolidinyl)phosphinic chloride (411 mg, 1.61 mmol) were stirred in DMF (3 ml) and triethylamine (0.4 ml) for 2 minutes. The solution was added to (R)-1-chloro-4-(2-methylpiperazin-1-yl)pyrido[3,4-d]pyridazine 59 (387 mg, 1.47 mmol) and washed in with an additional 1 ml DMF. The reaction was heated at 55° C. for 1.5 hours and then stirred at RT for 17 hours. The reaction was added to saturated NaHCO3 (80 ml) and extracted three times with dichloromethane (50 ml). The combined organics were dried (MgSO4) and evaporated to give a yellow solid. The residue was chromatographed over silica with a gradient of hexane and 0-100% ethyl acetate to give (R)-(4-(1-chloropyrido[3,4-d]pyridazin-4-yl)-3-methylpiperazin-1-yl)(4,4-difluorocyclohexyl)methanone 60 as a yellow solid, 236 mg. LC/MS m/z=410 (M+H+).

Provenance & Evidence