Cesium carbonate → tert-Butyl 9-methyl-7-(2-oxo-4-phenethylpiperazin-1-yl)-3,4-dihydro-1H-pyrido[3,4-b]indole-2(9H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

tert-Butyl 7-bromo-9-methyl-3,4-dihydro-1H-pyrido[3,4-b]indole-2(9H)-carboxylate (270 mg, 0.740 mmol), 4-phenethylpiperazin-2-one (150 mg, 0.735 mmol), CuI (140 mg, 0.735 mmol), trans-N,N′dimethylcyclohexane-1,2-diamine (104 mg, 0.735 mmol) and Cs2CO3 (311 mg, 0.956 mmol) in toluene (15 mL) were sparged with a nitrogen stream for 45 min and then stirred at 110° C. for 16 h. The mixture was diluted with 90:9:1 CH2Cl2/MeOH/NH4OH (50 mL) and washed with brine (3×50 mL). The resulting solution was dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by column chromatography eluting with methylene chloride and a 9:1 methanol/ammonium hydroxide mixture; gradient 100% methylene chloride to 85% methylene chloride, to provide the title compound (35 mg, 10%) as a yellow oil: ESI MS m/z 489 [M+H]+.

Provenance & Evidence