2,5-Piperazinedione → 2-[3-(2,5-Dioxo-piperazin-1-yl)-phenyl]-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid

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Reaction Conditions

Reaction Steps

A mixture of 2-(3-bromo-phenyl)-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid (360 mg, 1 mmol), piperazine-2,5-dione (570 mg, 5 mmol), copper(I) iodide (115 mg, 0.6 mmol), N,N-dimethylglycine hydrochloride (112 g, 0.8 mmol) and potassium carbonate (415 mg, 3 mmol) in dimethyl sulfoxide (5 mL) was stirred at 120° C. for 12 h. Then the reaction mixture cooled to room temperature. The reaction mixture was extracted with ethyl acetate (2×150 mL), washed with water (2×50 mL) and saturated aqueous ammonium chloride solution (2×50 mL), dried over anhydrous sodium sulfate and then concentrated in vacuo. Purification by Waters automated flash system (column: Xterra 30 mm×100 mm, sample manager 2767, pump 2525, detector: ZQ mass and UV 2487, solvent system: acetonitrile and 0.1% formic acid in water) afforded 2-[3-(2,5-dioxo-piperazin-1-yl)-phenyl]-3,3-dimethyl-1,2,3,4-tetrahydro-quinoline-6-carboxylic acid (46 mg, 11%) as a grey solid: LC/MS m/e calcd for C22H23N3O4 (M+H)+: 394.45, observed: 394.1.

Provenance & Evidence