Sodium Hydroxide → N-(6-hydroxy-1,3-benzothiazol-2-yl)cyclopropanecarboxamide

Participants

Reaction Steps

To a solution of 2-amino-1,3-benzothiazol-6-ol (3.43 g, 20.6 mmol) in pyridine (50 mL) were added cyclopropanecarbonyl chloride (4 mL, 44.1 mmol) and N,N-dimethylpyridine-4-amine (220 mg, 1.80 mmol), and the mixture was stirred at room temperature for 1.5 hr. To the reaction mixture was added lithium hydroxide monohydrate (2.06 g, 49.1 mmol) in water (50 mL) and the mixture was stirred at the same temperature for 1 hr. 5N Aqueous sodium hydroxide solution (50 mL) was added, and the mixture was stirred at room temperature for 2 days. The reaction mixture was concentrated under reduced pressure, and the residue was dissolved in dilute hydrochloric acid (300 mL, pH 2.0), and extracted with ethyl acetate (250 mL). The organic layer was washed with saturated aqueous sodium hydrogencarbonate solution (150 mL). The earlier aqueous layer was extracted with ethyl acetate (150 mL), and the organic layer was washed with saturated aqueous sodium hydrogencarbonate solution (100 mL). The collected organic layer was dried over anhydrous magnesium sulfate, the insoluble material was filtered off, and the filtrate was concentrated under reduced pressure to give the title compound (3.67 g, 76%) as a pale-gray solid.

Provenance & Evidence