Triethylamine → Piperidine-4-carboxylic acid (6-nitro-2,3-dioxo-1,2,3,4,7,8,9,10-octahydro-benzo[f]quinoxalin-9-yl) amide

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Reaction Conditions

Reaction Steps

N-t-butyloxycarbonylpiperidine-4-carboxylic acid (0.35 g, 1.5 mmol) and carbonyldiimidazole (0.24 g, 1.5 mmol) were refluxed in tetrahydrofuran (5 mL) for 15 min. The mixture was added to a solution of 9-amino-6-nitro-1,4,7,8,9,10-hexahydro-benzo[f]quinoxaline-2,3-dione (0.15 g, 1.5 mmol) in dimethylformamide (5 mL) and heated to 70° C. After 15 min, triethylamine (0.15 g, 1.5 mmol) was added and heating continued at 70° C. for 6 h. The solvent was removed by rotoevaporation in vacuo and the residue triturated with diethyl ether to form a solid. The solid was collected by filtration, washed with water and dried to give the crude product (0.23 g, 94% yield). For further purification, the solid was suspended and stirred in 2N HCl, and then filtered and dried. Anal. calc'd for C23H29N5O7.1.5 NaCl.H2O: C, 40.82; H, 4.57; N, 13.22; found-C, 40.35; H, 4.70:N, 12.91.

Provenance & Evidence