Sodium hydride → HCID 22404793, compound

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Reaction Steps

A 60% dispersion of sodium hydride in mineral oil (0.78 g, 0.019 mole) was placed in a flask, and the mineral oil was removed from it with two heptane washes. The sodium hydride was suspended in 40 mL of dry tetrahydrofuran, and this suspension was cooled to 0°-10° C. A solution of 2.96 g (0.0162 mole) of ethyl 3-amino-4,4,4-trifluorocrotonate in 5 mL of dry tetrahydrofuran was added dropwise to the suspension of sodium hydride. This mixture was then stirred at ambient temperature for 30 minutes. A solution of 4.40 g (0.0162 mole) of 4,6-dichloro-2,3-dihydro-2,2-dimethyl-benzofuran-3-on-7-yl isocyanate in 10 mL of dry tetrahydrofuran was added dropwise. Upon completion of addition, the reaction mixture was stirred at ambient temperature for 30 minutes and then was heated at reflux for three hours. At the conclusion of this period the mixture was diluted with water, and the resulting mixture was extracted three times with ethyl acetate. The combined extracts were dried over anhydrous magnesium sulfate, filtered, and the filtrate was evaporated under reduced pressure, yielding 9.58 g of a gummy, pale yellow residue. This residue was triturated with methylene chloride, yielding 4.79 g of 3-(4,6-dichloro-2,3-dihydro-2,2-dimethylbenzofuran-3-on-7-yl)-6-trifluoromethyluracil as an off-white solid, m.p. 308°-320° C. The NMR and IR spectra were consistent with the proposed structure.

Provenance & Evidence