HCID 54136697, compound → HCID 15336052, compound

Participants

Reaction Steps

A mixture of 6.0 g of ethyl(2,3,4,5-tetrafluorobenzoyl)acetate, 5.8 g of ethyl orthoformate and 6.3 g of acetic anhydride was refluxed for 2 hours. After distillation under reduced pressure, the residue was dissolved in 50 ml of ethanol. To this solution, 2.8 g of 2-aminomethylthiazole was added, followed by stirring for 2 hours, while ice cooling. The reaction product was added to 100 ml of ice water, and the resulting crystal was collected by filtration and dried. The 8.0 g crystal obtained was dissolved in 50 ml of dimethylformamide, and 2.0 g of 60% oily sodium hydride was added, followed by heating and stirring at 100 to 110° C. for 2 hours. The reaction product was added to 100 ml of ice water and extracted with dichloromethane (100 ml ×3). The extract was washed with water and dried over anhydrous magnesium sulfate, after which the solvent was distilled off under reduced pressure, to yield 5.4 g of ethyl 1-(thiazol-2-yl)methyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylate. Next, 5.0 g of this ester was dissolved in a mixture of 3 ml of sulfuric acid, 20 ml of acetic acid and 18 ml of water, followed by stirring at 110° to 120° C. for 1.5 hours. The reaction product was added to 100 ml of ice water to cause crystallization. The resulting crystal was collected by filtration, washed with water and dried to yield 4.4 g of the title compound.

Provenance & Evidence