Triethylamine → 1,1-Dimethylethyl 4-[(1,2,3,4,7,8,9,10-octahydro-2,3-dioxopyrido[3,4-f]quinoxaline-9-yl)carbonyl]-1-piperidine carboxylate

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Reaction Conditions

Reaction Steps

A solution of N-Boc-4-piperidinecarboxylic acid (158 mg, 0.69 mmol) and carbonyldiimidazole (119 mg, 0.69 mmol) in tetrahydrofuran (3 mL) under a nitrogen atmosphere was reluxed for 15 min. This solution was then added to suspension of the quinoxalinedione from Example 30 (100 mg, 0.46 mmol) in anhydrous dimethylformamide (3 mL). After stirring for 15 min (nitrogen atmosphere), triethylamine (0.96 mL, 0.69 mmol) was added and the reaction was stirred at 70° C. for 19 h. The mixture was concentrated to dryness and the residue triturated with water and collected by filtration. A beige solid (143 mg, 73% yield) was obtained. mp=283-286° C. CHN calc'd for C22H28N4O5 within ±0.4.

Provenance & Evidence