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

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 in externally cooling condition and then the reaction was slowly warmed to room temperature. After refluxing 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 (2×100 ml), dried over Na2SO4 and concentrated. The residue obtained was purified by silica gel column chromatography using 5% ethyl acetate in chloroform to obtain 21 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).

1. temperaturein externally cooling condition
2. temperatureAfter refluxing for 3 h the reaction mixture
3. temperatureto cool to 0° C.
4. customquenched with ice cold water (350 ml)
5. extractionThe reaction mixture was extracted with chloroform (2×200 ml)
6. washthe combined organic extracts were washed with water (2×100 ml)
7. dry with materialdried over Na2SO4
8. concentrationconcentrated
9. customThe residue obtained
10. customwas purified by silica gel column chromatography

ORD record

ord-1d328d246cec4ea29b5aced902a2bed1

Source dataset

uspto-grants-2014_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08623880B2