Potassium Cyanide → 6-Amino-2-cyanobenzothiazole

Participants

Reaction Conditions

Reaction Steps

Potassium cyanide (1.29 g, 19.7 mmol) was added to dimethyl sulfoxide (DMSO, 150 mL). After argon substitution, the mixture was refluxed overnight at 135° C. with stirring. The temperature was lowered to 120° C., and Compound 3 (1.02 g, 5.55 mmol) dissolved in DMSO (20 mL) was added. After disappearance of the starting materials was confirmed by thin layer chromatography (developing solvent: ethyl acetate/n-hexane=2/1), the reaction mixture was poured into a mixed solution of 1.0 mol/L potassium dihydrogenphosphate solution (100 mL) and diethyl ether, (150 mL), and the diethyl ether layer was separated. The aqueous layer was extracted 5 times with ethyl acetate, the organic layer was mixed with the diethyl ether layer, and this organic solvent layer was washed twice with purified water and twice with saturated brine. The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (developing solvent: ethyl acetate/n-hexane=1/4 to 1/2) to obtain Compound 4 as yellow solid (521 mg, 54% yield).

Provenance & Evidence