Diphenylacetic Acid → 5-Diphenylacetyl-1,3-dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,3-dimethylbarbituric acid (5.00 g, 32.05 mmol), diphenylacetic acid (10.19 g, 48.03 mmol), 4-dimethylaminopyridine (1.95 g, 16.01 mmol) in dry CH2Cl2 (30 ml) was cooled to 0° C. and 1,3-dicyclohexylcarbodiimide (7:26 g, 35.22 mmol) added. The reaction mixture was stirred at room temperature overnight and filtered. The solid was washed with CH2Cl2 (150 ml) and the combined solution was washed with 2 N HCl solution (40 ml). The organic phase was dried over MgSO4 and evaporated. The residue was crystallized from EtOH giving 5-diphenylacetyl-1,3-dimethyl-2,4,6(1H,3H,5H)-pyrimidinetrione 9 (6.70 g, 59%).

Provenance & Evidence