Triethylamine → 5-Bromo-3-(4-((S)-1,4-dimethyl-3-oxopiperazin-2-yl)phenylamino)-1-methylpyrazin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

To a single-necked 250 mL round-bottomed flask equipped with a magnetic stirrer and reflux condenser was charged (−)-1,4-dimethyl-3-(4-aminophenyl)piperazin-2-one (8.2 g, 37.3 mmol), 3,5-dibromo-1-methylpyrazin-2(1H)-one (10.0 g, 37.3 mmol), and i-PrOH (100 mL). Triethylamine (5.72 mL, 41 mmol, 1.1 eq) was then added and the resulting suspension was heated at 80° C. for 16 hrs. A thick slurry was observed the following day. The reaction was cooled to room temperature then concentrated in vacuo to ˜20 mL total volume. At that point 20 mL of 2M Na2CO3 solution was added followed by 100 mL of water. The mixture was then allowed to slurry for 2 hrs at room temperature. The off-white solid was then collected on a fritted funnel and allowed to air dry for ˜1 hr. The solids were returned to the reaction flask and 100 mL of diethyl ether/hexanes (1:1) was added and the suspension was triturated at room temperature for 1 hr. The white solid was then collected on a fritted funnel, dried on the filter with vacuum for 1 hr, then transferred to a round-bottomed flask and vacuum-dried overnight. White solids were obtained, 12.88 g (85%).

Provenance & Evidence