Phosphorus oxychloride → 6-chloro-3-cyclopropyl-1-(3-nitrophenyl)-1H-pyrimidine-2,4-dione

Participants

Reaction Conditions

Reaction Steps

To 1-cyclopropyl-3-(3-nitrophenyl)pyrimidine-2,4,6-trione 5 (28 g) obtained in Step 2 was added water (3 ml), phosphorus oxychloride (72 ml) was added dropwise by small portions with stirring, and the mixture was stirred with heating at 110° C. for 1 hr. The reaction mixture was poured into ice water by small portions, and the precipitated solid was filtered by suction. The filtrate was dissolved in chloroform (300 ml), washed with water (30 ml) and brine (30 ml), and the organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by column chromatography (chloroform:acetone=9:1) to give a 2:1 mixture (10 g, 34%) of 6-chloro-3-cyclopropyl-1-(3-nitrophenyl)-1H-pyrimidine-2,4-dione 6 and 4-chloro-3-cyclopropyl-1-(3-nitrophenyl)-1H-pyrimidine-2,6-dione 7 as a white solid.

Provenance & Evidence