Trifluoroacetic acid → 1-(5-Phenyl-1,3,4,5-tetrahydro-pyrido[4,3-b]indol-2-yl)-2-(4,7-dimethoxy-6-azaindol-3-yl)-ethane-1,2-dione

Participants

Reaction Steps

General Method: A solution of 5-phenyl-1,3,4,5-tetrahydro-pyrido[4,3-b]indole-2-carboxylic acid tert-butyl ester (0.054 g, 0.155 mmol) in dry CH2Cl2 (2 mL) was treated with TFA (0.20 mL). After stirring the mixture for 1 h, the solvent was evaporated in vacuo and the residue was dissolved in CHCl3 (5 mL). To this mixture was added 4,7-dimethoxy-6-azaindol-3-yl-oxoacetic acid (0.042 g, 0.155 mmol), i-Pr2NEt (0.27 mL, 1.55 mmol) and then BOP-Cl (0.039 g, 0.153 mmol). The mixture was allowed to stir at room temperature for 2 h and then the solvent was removed in vacuo. The residue was partitioned with EtOAc-H2O, the organic phase was separated and the aqueous phase was re-extracted with EtOAc (2×). The combined organic layers were washed (H2O, brine), dried (Na2SO4) and evaporated. The residue was purified by preparative HPLC to give the title compound (0.025 g, 33%) as a white solid. 1H NMR (400 MHz, CDCl3) δ 9.27 (s, 0.67H), 9.22 (s, 0.33H), 8.06 (d, J=3.0 Hz, 0.67H), 8.00 (d, J=3.0 Hz, 0.33H), 7.59-7.07 (m, 10H), 4.11 (m, 1H), 4.05 (s, 3H), 3.88 (s, 1H), 3.85 (m, 2H), 3.72 (s, 2H), 2.88 (m, 1H), 2.78 (m, 2H); LCMS: m/e 481 (M+H)+.

Provenance & Evidence