Citric Acid → 3-Cyclopropyl-1-(2-fluoro-4-iodophenyl)-6-(methylamino)-2,4(1H,3H)-pyrimidinedione

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Reaction Steps

Under a nitrogen atmosphere, to t-butanol-ethanol [2:1 (volume ratio), 250 ml] was added sodium borohydride (6.41 g), and the mixture was stirred at room temperature for 1 hr. Under water-cooling, N′-[1-cyclopropyl-3-(2-fluoro-4-iodo-phenyl)-2,6-dioxo-1,2,3,6-tetrahydro-pyrimidin-4-yl]-N,N-dimethyl-formamidine 76 (50.0 g) was added, and the mixture was stirred for 2.5 hrs. Under water-cooling, water (225 ml) and 10% aqueous citric acid solution (175 ml) were successively added dropwise, and the mixture was stirred for 3 hrs. The precipitated crystals were collected by filtration and dried to give crude crystals (34.5 g, LC purity 91%) of 3-cyclopropyl-1-(2-fluoro-4-iodo-phenyl)-6-methylamino-1H-pyrimidine-2,4-dione 52, which were used for the next reaction without purification.

Provenance & Evidence