Sodium Hydroxide → 7-Hydroxyiminomethylimidazo[5,1-b]thiazole

Participants

Reaction Steps

7-Formylimidazo[5,1-b]thiazole (249 mg) was suspended in 10 ml of ethanol. Hydroxylamine hydrochloride (137 mg) and 2.0 ml of a 1 N aqueous sodium hydroxide solution were added under ice cooling to the suspension. The mixture was stirred at the same temperature for 1.5 hr, and then stirred at room temperature for 3 hr. The reaction solution was concentrated under the reduced pressure until the volume of the reaction solution was reduced to approximately the half of the original volume. The concentrate was adjusted to pH 12 by the addition of a potassium carbonate solution, followed by extraction three times with dichloromethane. The extract was dried over anhydrous magnesium sulfate. The solvent was removed by distillation under the reduced pressure. The residue was purified by column chromatography on silica gel (dichloromethane:ethyl acetate=1:2). Of two main components, the fraction, which had been eluted earlier, was collected to give 160 mg of 7-hydroxyiminomethylimidazo[5,1-b]thiazole (a low-polarity geometrical isomer).

Provenance & Evidence