Hydrochloric Acid → HCID 66599056, compound

Participants

Reaction Steps

A solution of 4-[(2-chloro-4-fluorophenyl)carbonyl]-2-piperazinone (0.257 g, 1 mmol, e.g. prepared as described in Intermediate 2) in dry Dichloromethane (DCM) (2 ml) was stirred at room temperature under argon. Triethyloxonium tetrafluoroborate (0.190 g, 1.000 mmol) was added and the reaction solution was stirred for 3 hours. 3-Methyl-2-pyridinecarbohydrazide (0.166 g, 1.100 mmol, e.g. prepared as described in Intermediate 22) was added to the solution and stirred for 1 h. The solvent was then evaporated in vacuo and n-butanol (2.000 ml) was added to the residue. The solution was heated at reflux for 18 hours and then allowed to cool to room temperature. The solvent was then evaporated in vacuo and the residue was partitioned between Dichloromethane and brine. The organic layer was dried over sodium sulphate, filtered and the solvent was evaporated in vacuo to give a yellow solid. The solid was then purified by flash chromatography (Biotage SP4, 25+M cartridge) using a gradient of 0 to 10% MeOH/NH3 in Dichloromethane as the eluent. The solvent was then evaporated in vacuo and the remaining residue was purified by mass-directed automated (preparative) HPLC (MDAP) to yield the crude product. The product was then dissolved in methanol (2 mL) and to this was added HCl in diethyl ether (1 mL), the solvent was then evaporated in vacuo and dried in a vacuum-oven yielding 7-[(2-chloro-4-fluorophenyl)carbonyl]-3-(3-methyl-2-pyridinyl)-5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyrazine (0.108 g).

Provenance & Evidence