5980-26-7

106-46-7

127099-85-8

5980-26-7

GENERAL SYNTHESIS: Cyanoguanidine (0.084 g, 1 mmol) was suspended in 2 mL of pure aromatic solvent (or the aromatic hydrocarbon can be suspended in CH2Cl2) and freshly distilled trifluoromethanesulfonic acid (0.5 mL, 6 mmol) was added slowly and dropwise. The reaction mixture was stirred at 60 °C for 2 h, followed by the addition of 1 mL of cold water. Stirring of the mixture was continued overnight. Product separation was accomplished by alkalinizing the reaction mixture with 10 M NaOH and extracting twice with chloroform. The organic phases were combined, washed sequentially with water and saturated saline and dried over anhydrous MgSO4. The crude product can be further purified by silica gel column chromatography (eluent: hexane/ethyl acetate).