Triethylamine → 2,3-Di-p-tolyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine

Participants

Reaction Steps

A solution of 2,3-dip-tolylpyrido[2,3-b]pyrazine (step 1) (181 g, 487 mmol) in EtOH/THF (1:2, 2100 ml) was treated with 10% palladium on carbon (30 g, 28.8 mmol) and the reaction mixture was placed under 0.1 bar of hydrogen at RT. After 2 days and 4 days respectively, additional batches of 10% palladium on carbon (10 g, 9.6 mmol, twice) were added along with Et3N (85 ml, 706 mmol, twice). After 7 days in total, the reaction mixture was filtered through Hyflo (filter material) and washed through with THF (2.5 L in portions). The filtrate was concentrated in vacuo to give a green/yellow solid. The solid was triturated with 1:1 TBME/heptane (500 ml) and filtered. The solid was washed with 1:1 TBME/heptane (200 ml) to give a pale yellow solid which was dried overnight to afford the title compound; HPLC (Agilent 1200), Rt 4.73 min, Method B.

Provenance & Evidence