Phosphorus oxychloride → 6-Chloro-1,3-dimethyl-2,4(1H,3H)-pyrimidinedione

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 1,3-dimethylbarbituric acid (20.0 g, 128.09 mmol) in water (10 ml), phosphorous oxychloride (80 ml) was added slowly by externally cooling and reaction was then refluxed for 3 h. The reaction mixture was allowed to cool to 0° C. and quenched with ice cold water (350 ml). The reaction mixture was extracted with chloroform (2×200 ml) and the combined organic extracts were washed with water, dried over Na2SO4 and concentrated to obtain 21.0 g of the product as a pale brown solid; 1H NMR (300 MHz, CDCl3) δ 3.33 (s, 3H), 3.57 (s, 3H), 5.94 (s, 1H).

Provenance & Evidence