Dimethylformamide → 5-bromo-2-chloro-4-[(E)-2-ethoxyvinyl]pyrimidine

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Reaction Steps

A mixture of 3.11 g of 5-bromo-2,4-dichloropyrimidine, 5.18 g of cis-1-ethoxy-2-tri-n-butylstannylethylene (synthesized according to the method disclosed in J. Am. Chem. Soc., 1977, 99, 7365), 0.479 g of dichlorobis(triphenylphosphine)palladium (II), and 60 mL of N, N-dimethylformamide was stirred for 6 hours at 70° C. After standing to cool, 60 mL of water, 60 mL of ethyl acetate, and 20 g of potassium fluoride were added thereto, and the mixture was stirred overnight at room temperature. The insolubles were filtered through celite and the filtrate was extracted with chloroform. The obtained organic layer was washed with water and saturated brine in that order, and dried over anhydrous sodium sulfate. The insolubles were filtered, the filtrate was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (eluent: 10% chloroform-hexane/ethylacetate=100/0-0/100), to obtain 1.15 g of 5-bromo-2-chloro-4-[(E)-2-ethoxyvinyl]pyrimidine [11-1] (hereinafter, referred to as the compound [11-1]) as a pale yellow solid.

Provenance & Evidence