4-Methylmorpholine → methyl N-[(5-amino-1-methyl-3-phenyl-1H-indol-2-yl)carbonyl]-L-leucinate

Participants

Reaction Steps

A mixture of 1-methyl-5-nitro-3-phenyl-1H-indole-2-carboxylic acid (0.56 g, 1.9 mmol), 1-[3-(dimethylamino)propyl-3-ethylcarbodiimide hydrochloride (0.47 g, 2.5 mmol), and L-leucine methyl ester hydrochloride (0.40 g, 2.2 mmol) was stirred in CH2Cl2 (20 mL). N-methylmorpholine (1.01 g, 10 mmol) was added and the mixture was stirred at room temperature overnight. The mixture was then washed with 0.05 N HCl and water. The resulting solution was dried with MgSO4 and concentrated. The residue was dissolved in 30 mL of ethanol and a large excess of Raney® nickel and hydrazine (0.6 mL, 19 mmol) were added. After stirring at room temperature for 2 h the catalyst was then removed by filtering through a short pad of Celite®521. The filtrate was concentrated to give 0.65 g (87%) of crude methyl N-[(5-amino-1-methyl-3-phenyl-1H-indol-2-yl)carbonyl]-L-leucinate as a pale yellow solid: MS (ESI) m/z 394 (MH+); HRMS calcd for C23H28N3O3: 394.2128; found (ESI+): 394.2121.

Provenance & Evidence