Ethylenediamine → 7-((4-methoxybenzyl)oxy)-3,4-dihydro-1H-pyrido[1,2-a]pyrazine-1,8(2H)-dione

Participants

Reaction Conditions

Reaction Steps

The mixture of 5-((4-methoxybenzyl)oxy)-4-oxo-4H-pyran-2-carboxylic acid (Example 2b) (5.24 g, 18.21 mmol), ethane-1,2-diamine (1.830 mL, 27.3 mmol) in water (80 mL) was stirred at 60° C. for 1 h and then 80° C. for 20 h. Yellow solid precipitated from the reaction when heating. After cooling, white precipitate was filtered off, washed with 20 mL of cold water/acetone (v:v=1:1) and dried to give 7-((4-methoxybenzyl)oxy)-3,4-dihydro-1H-pyrido[1,2-a]pyrazine-1,8(2H)-dione (4.15 g, 13.82 mmol, 76% yield) as white solid, which was used in the next step without further purification. LCMS (M+H)+: 301.2

Provenance & Evidence