Benzamidine, hydrochloride → 2-(4-Methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of benzamidine hydrochloride (9.2 g; 50 mmol) in methanol (46 mL) was slowly added a solution of sodium methoxide (25%) (23 mL; 100 mmol) and dimethyl 2-acetyl-3-propylsuccinate (60%) (19.2 g; 50 mmol). The reaction mixture was heated at reflux for 18 h, and after cooling, the white precipitate was filtered and washed with a small volume of methanol. The solid was dried and carefully added to a cold hydrochloric 12N solution (25 mL). The suspension was stirred for one minute at 0° C., filtered and washed with a small amount of methanol. The precipitate was dried under reduced pressure over phosphorus pentoxide to provide 17.16 g of the expected 2-(4-methyl-6-oxo-2-phenyl-1,6-dihydropyrimidin-5-yl)pentanoic acid as a white powder which was used without further purification. ESI/APCI(+): 287 (M+H); ESI/APCI(−): 285 (M−H). 1H NMR (DMSO-d6) δ 8.08 (2H, d, Harom.); 7.70 (1H, m, Harom.); 7.60 (2H, m, Harom.); 3.76 (1H, m, CHα); 2.48 (3H, s, CH3); 1.98 (1H, m, CHβ); 1.72 (1H, m, CHβ′); 1.14 (2H, m, CH2γ); 0.87 (3H, t, CH3δ).

Provenance & Evidence