Aluminum(III) Chloride → 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-4,5-dicyano-3-methyl-1,3-dihydro-2H-imidazol-2-one

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Reaction Steps

The product of Example 29, 1-(4-chloro-2-fluoro-5-methoxyphenyl)-4,5-dicyano-3-methyl-1,3-dihydro-2H-imidazol-2-one (VI) (2.7 g, 8.82 mmol) was stirred in 100 mL benzene. To this mixture was added AlCl3 (4.68 g, 35.3 mmol) and the mixture was heated to reflux for 15 minutes. The mixture was cooled to room temperature, poured onto water, and extracted three times with 100 mL ethyl acetate. The organic solution was washed with water and brine, dried over MgSO4, filtered, and evaporated. The crude product was purified by elution from a short silica gel column. Recrystallization with ethyl acetate/heptane gave 1.6 g of 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-4,5-dicyano-3-methyl-1,3-dihydro-2H-imidazol-2-one (VIII) (m.p. 210°-12° C.).

Provenance & Evidence