Ethyl Acetate → 3-(5-chloro-3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)-6-trifluoromethyluracil

Participants

Reaction Steps

By a method analogous to that of Example 1, Step G, 2.5 grams (0.011 mole) of 5-chloro-3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl isocyanate was reacted with ethyl 3-amino-4,4,4-trifluorocrotonate and 0.66 gram (0.012 mole) of sodium hydride (60% in mineral oil) in 150 mL of tetrahydrofuran. The crude reaction product was subjected to column chromatography on silica gel, with 1:2 ethyl acetate:hexane as the eluant. The product-containing fractions were combined and concentrated under reduced pressure, yielding 3.0 grams of 3-(5-chloro-3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)-6-trifluoromethyluracil. The NMR spectrum was consistent with the proposed structure.

Provenance & Evidence