Benzoyl chloride, 3-chloro- → 6-[4-[5-(3-Chlorophenyl)-1,2,4-oxadiazol-3-yl]piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine

Participants

Reaction Conditions

Reaction Steps

3-Chlorobenzoyl chloride (92 mg, 0.53 mmol) was added to a stirred partial solution of N-hydroxy-4-[3-(trifluoromethyl)-[1,2,4]triazolo[4,3-b]pyridazin-6-yl]piperazine-1-carboximidamide (165 mg, 0.5 mmol) and DIPEA (97 mg, 0.75 mmol) in THF (3 mL). The reaction mixture became a clear solution over 30 minutes and LCMS after 1 hour showed complete initial acylation. The reaction mixture was heated at 150° C. for 15 minutes by microwave after which LCMS showed complete cyclisation to the desired product. The reaction mixture was evaporated and the residue was boiled briefly with ethanol, cooled and filtered off to give 6-[4-[5-(3-chlorophenyl)-1,2,4-oxadiazol-3-yl]piperazin-1-yl]-3-(trifluoromethyl)[1,2,4]triazolo[4,3-b]pyridazine (104 mg, 46%) as a crystalline powder.

Provenance & Evidence