Dimethylformamide → 2-Butyl-5-chloro-1H-imidazole-4-carbaldehyde

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

2-n-Butyl-2-imidazolin-5-one (9.81 g, 70 mmol) was added to a solution of phosphoroxychloride (26.83 g, 175 mmol) in chlorobenzene (50 ml) at room temperature. The orange suspension was heated to 100° C. within 5 minutes, and then N,N-dimethylformamide (12.79 g, 175 mmol) was added within 3 minutes. The black mixture was kept for 2 hours at 100° C., cooled to 40° C. and poured on water (84 ml). After addition of ethyl acetate (42 ml), the mixture was stirred for 15 minutes at 26° to 28° C. and then adjusted to pH 7 by addition of 30 percent sodium hydroxide solution (67 ml). The phases were separated, and the aqueous phase was extracted twice with 70 ml of ethyl acetate each. The combined organic phases were dried (MgSO4), filtered and concentrated by evaporation on a Rotavapor. The title compound was obtained in a yield of 8.31 g (64 percent) relative to the 2-n-butyl-2-imidazolin-5-one.

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