35665-38-4

556-50-3

28920-43-6

35665-38-4

General procedure for the synthesis of N-fluorenylmethoxycarbonyl-glycyl-glycine from bisglycopeptide and chloroformic acid-9-fluorenylmethyl ester: 15 mL of dioxane was added to a mixture of bisglycopeptide (1 mmol) and chloroformic acid-9-fluorenylmethyl ester (1.2 mmol), cooled to 0 °C and then an equal volume of a 1N Na2CO3 solution was slowly added. The reaction mixture was stirred at room temperature for 12 hours. The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming the completion of the reaction, the reaction solution was acidified to pH 4-5 with 1 M HCl. The reaction mixture was extracted with ethyl acetate (3 x 70 mL) at 0 °C. The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to afford pure N-fluorenylmethoxycarbonyl-glycyl-glycine in 89% yield.