Sulfuric Acid → 6-(4-chloro-2-pyridin-3-yl-benzyl)-9-hydroxy-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione

Participants

Reaction Steps

To a stirred solution of 9-benzyloxy-6-(4-chloro-2-pyridin-3-yl-benzyl)-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (389) (45 mg, 0.088 mmol) in acetic acid (2 mL), concentrated H2SO4 (0.001 mL, 0.018 mmol) was added and the reaction mixture was stirred for 4 h at room temperature (monitored by LC-MS). From the reaction, volatiles were removed and the residue was quenched with ice col d water (5 mL). Aqueous saturated NaHCO3 was added to adjust the pH up to 8. The quenched mass was extracted with ethyl acetate (2×15 mL), the combined organic part was dried, concentrated and purified by preparative HPLC to get 6-(4-chloro-2-pyridin-3-yl-benzyl)-9-hydroxy-2-isopropyl-3,4-dihydro-2H-pyrazino[1,2-c]pyrimidine-1,8-dione (390) (12.0 mg, 32.26%) as an off-white solid.

Provenance & Evidence