TEA in water; N,N-dimethyl-formamide T=20°C; Acylation;

1.1: H2SO4 1.2: pyridine / ethanol 2.1: triethylamine / dimethylformamide View Scheme

triethylamine in N,N-dimethyl-formamide

1.1: H2SO4 1.2: pyridine / ethanol 2.1: triethylamine / dimethylformamide View Scheme

triethylamine in water; N,N-dimethyl-formamide

1: NaNO2; aq. acetic acid View Scheme

Condensation;

1: 86.8 percent / dicyclohexylcarbodiimide (DCC) / ethyl acetate / 2 h / 0 °C 2: 70.8 percent / 25percent aq. ammonia / tetrahydrofuran / 2 h / Ambient temperature 3: CF3COOH / 0.25 h / Ambient temperature 4: acetonitrile / 15 h / Ambient temperature 5: CF3COOH / 0.33 h / Ambient temperature 6: acetonitrile / 15 h / Ambient temperature 7: 85.4 percent / H2, AcOH / Pd black / methanol / 3 h / Ambient temperature View Scheme

1: DCC / tetrahydrofuran 2: 25 percent aq. NH4OH 3: acetic acid / 5 percent Pd/C / 72 h View Scheme

1: DCC / tetrahydrofuran 2: 25 percent aq. NH4OH 3: acetic acid / 5 percent Pd/C / 72 h 4: 50 percent TFA / CH2Cl2 5: 20 percent aq. NaHCO3 / CH2Cl2 / 72 h / 20 °C View Scheme