1: 96 percent / N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / dimethylformamide / 10 h. 0 deg C, 10 h. room temp. 2: H2O, NaOH / methanol 3: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / formamide / 10 h. 0 deg C, 10 h. room temp. 4: H2O, NaOH / methanol 5: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / dimethylformamide 6: H2O, NaOH / methanol 7: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / dimethylformamide 8: NH3 / methanol 9: HCl, acetic acid / various solvent(s) / 1.5 h View Scheme

1: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / dimethylformamide 2: H2O, NaOH 3: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / formamide 4: H2O, NaOH / methanol 5: N-hydroxybenzotriazole, triethylamine, dicyclohexylcarbodiimide / dimethylformamide 6: NH3 / methanol 7: HCl, acetic acid / various solvent(s) View Scheme