O.Cl.[C:3]([NH2:11])(=[NH:10])[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1.C[O-].[Na+].[CH2:15]([CH:17]([C:23](OCC)=[O:24])[C:18](OCC)=[O:19])[CH3:16]>CO>[CH2:15]([C:17]1[C:18](=[O:19])[NH:10][C:3]([C:4]2[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=2)=[N:11][C:23]=1[OH:24])[CH3:16]A mixture of 45.19 g (0.29 mol) of benzamidine hydrochloride hydrate, 127.42 g (0.59 mol) of 25% sodium methoxide in methanol, 55 mL (0.29 mol) of diethyl ethylmalonate and 175 mL of methanol was heated at reflux for 25 h. The mixture was rotovapped to remove the bulk of the methanol. The residue was diluted with 300 mL of water and the pH was adjusted to 7 with concentrated hydrochloric acid. The solid precipitate was collected by filtration and dried under vacuum at 50° C. to afford 31.89 g (51%) of crude 5-ethyl-6-hydroxy-2-phenyl-4(3H)-pyrimidinone as a pale yellow solid. 1H-NMR (d6-DMSO) δ 1.05(3H,t), 2.39(2H,q), 7.5(3H,m), 8.1(2H,m).
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