Potassium Carbonate → 2-(4-Pyridinyl)-8-(trifluoromethyl)-6,7,8,9-tetrahydro-4H-pyrimido[1,2-a]pyrimidin-4-one

A mixture of 5.62 g (29.09 mmol) of ethyl 3-(pyridin-4-yl)-3-oxopropionate, 7 g (29.09 mmol) of 6-(trifluoromethyl)-1,4,5,6-tetrahydro-2-pyrimidinamine hydrochloride (1:2) and 10.05 g (72.72 mmol) of potassium carbonate in 50 ml of ethanol was heated at reflux temperature for 12 h. The cooled solution was evaporated to remove solvent, the residue was treated with water and the precipitate was filtered to give 4.82 g of product as a yellow powder.