Sodium hydride → Ethyl 6,7,8-trifluoro-1-(4-thiazolylmethyl)-1,4-dihydro-4-oxoquinoline-3-carboxylate

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Reaction Conditions

Reaction Steps

1.5 g of ethyl 6,7,8-trifluoro-4-hydroxyquinoline-3-carboxylate was dissolved in 30 ml of DMF, and 0.43 g of 60% oily sodium hydride was added, followed by stirring at 80° C. in a nitrogen gas stream for 20 minutes. To this solution, 1.9 g of 4-chloromethylthiazole hydrochloride was added, followed by stirring at constant temperature for 15 hours, after which the reaction mixture was concentrated to dryness. The residue was dissolved in CHCl3 ; the organic layer was washed with water and dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (hexane-ethyl acetate=1:2) to yield 0.46 g of ethyl 6,7,8-trifluoro-1-(4-thiazolylmethyl)-1,4-dihydro-4-oxoquinoline-3-carboxylate as a colorless powder. This product was suspended in a mixture of acetic acid and water (3 ml:3 ml); 0.33 ml of sulfuric acid was added, followed by stirring at 120° C. for 30 minutes. The reaction mixture was allowed to cool to room temperature, and the resulting crystal was collected by filtration to yield 0.38 g of the title compound as a colorless powder.

Provenance & Evidence