Acetic Anhydride → HCID 54154309, compound

Participants

Reaction Conditions

Reaction Steps

To ethyl 2-chloro-4,5-difluoro-3-methylbenzoylacetate (3.9 g) are added triethoxymethane (3.1 g) and acetic anhydride (3.4 g), and the mixture is heated at 150° C. for one hour. The mixture is concentrated to give ethyl 2-(2-chloro-3-methyl-4,5-difluorobenzoyl)-3-ethoxyacrylate. To the product is added ethanol (50 ml) and thereto is added cyclopropylamine (1.1 ml) at room temperture, and the mixture is stirred for 30 minutes. Ethanol is distilled off to give ethyl 2-(2-chloro-3-methyl-4,5-difluorobenzoyl)-3-cyclopropylaminoacrylate. To the product is added anhydrous dioxane (30 ml) and thereto is added portionwise 60% sodium hydride (0.6 g). The mixture is stirred at room temperature for 30 minutes and then refluxed for one hour. The reaction mixture is poured into aqueous saturated ammonium chloride and extracted with dichloromethane. The extract is dried over magnesium sulfate and concentrated to give ethyl 1-cyclopropyl-6,7-difluoro-8-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (2.2 g).

Provenance & Evidence