1,2-dihydro-2-oxo-Imidazo[1,5-a]pyrimidine-8-carboxylic acid ethyl ester synthesis

Yield:222292-69-5 37.4%

Reaction Conditions:

with triethylamine in acetonitrile at 50; for 16 h;

Steps:

49.2 Synthesis of ethyl 2-oxo-1,2-dihydroimidazo[1,5-a]pyrimidine-8-carboxylate:

A solution of ethyl 5-amino-1H-imidazole-4-carboxylate (10.0 g, 64.5 mmol), 2,5- dioxopyrrolidin-l-yl 3-(2,5-dioxopyrrolidin-l-yloxy)acrylate (20.01 g, 70.9 mmol), and triethylamine (13.02 g, 129 mmol) in anhydrous acetonitrile (200 mL) was heated to 50 °C for 16 h. After concentration in vacuo, the residue was treated with MeOH (100 mL), and the mixture was stirred at 60 °C for 30 min. The mixture was filtered, and the filtrate was concentrated and purified via silica gel column chromatography (MeOH/CH₂Cl₂ , 4:96 v/v) to give ethyl 2-oxo-1,2-dihydroimidazo[1,5-a]pyrimidine-8-carboxylate (5.0 g, 37.4%) as a white solid. MS (ESI) calcd for C₉H₉N₃O₂: 207.06

References:

WO2013/59587,2013,A1 Location in patent:Page/Page column 152