By cyclocondensation of 3-chloro-6-fluoro-2-(trifluoromethyl)benzaldehyde (I), isopropyl 3-aminocrotonate (II) and methyl 4-fluoroacetylacetate (III) by heating at 110 C. The starting products are prepared as follows: Aldehyde (I) is obtained by reaction of 1-chloro-4-fluoro-3-(trifluoromethyl)benzene (IV) with N-methyl-N-phenylformamide (V) by means of butyllithium in TNF. Aminocrotonate (II) is obtained by reaction of isopropyl acetoacetate (VI) with dry ammonia in methanol. Finally, the acylation of 2,2-dimethyl-1,3-dioxane-4,6-dione (VII) with fluoroacetyl chloride (VIII) by means of pyridine in dichloromethane gives 5-(fluoroacetyl)-2,2-dimethyl-1,3-dioxane-4,6-dione (IX), which is then treated with refluxing methanol to give 4-fluoroacetylacetate (III).

By cyclocondensation of 3-chloro-6-fluoro-2-(trifluoromethyl)benzaldehyde (I), isopropyl 3-aminocrotonate (II) and methyl 4-fluoroacetylacetate (III) by heating at 110 C. The starting products are prepared as follows: Aldehyde (I) is obtained by reaction of 1-chloro-4-fluoro-3-(trifluoromethyl)benzene (IV) with N-methyl-N-phenylformamide (V) by means of butyllithium in TNF. Aminocrotonate (II) is obtained by reaction of isopropyl acetoacetate (VI) with dry ammonia in methanol. Finally, the acylation of 2,2-dimethyl-1,3-dioxane-4,6-dione (VII) with fluoroacetyl chloride (VIII) by means of pyridine in dichloromethane gives 5-(fluoroacetyl)-2,2-dimethyl-1,3-dioxane-4,6-dione (IX), which is then treated with refluxing methanol to give 4-fluoroacetylacetate (III).

By cyclocondensation of 3-chloro-6-fluoro-2-(trifluoromethyl)benzaldehyde (I), isopropyl 3-aminocrotonate (II) and methyl 4-fluoroacetylacetate (III) by heating at 110 C. The starting products are prepared as follows: Aldehyde (I) is obtained by reaction of 1-chloro-4-fluoro-3-(trifluoromethyl)benzene (IV) with N-methyl-N-phenylformamide (V) by means of butyllithium in TNF. Aminocrotonate (II) is obtained by reaction of isopropyl acetoacetate (VI) with dry ammonia in methanol. Finally, the acylation of 2,2-dimethyl-1,3-dioxane-4,6-dione (VII) with fluoroacetyl chloride (VIII) by means of pyridine in dichloromethane gives 5-(fluoroacetyl)-2,2-dimethyl-1,3-dioxane-4,6-dione (IX), which is then treated with refluxing methanol to give 4-fluoroacetylacetate (III).