Potassium Carbonate → 4-[3-(6,7-Dimethoxy-3-styryl-quinoxalin-2-ylamino)-propyl]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

A mixture 2-chloro-6,7-dimethoxy-3-styryl-quinoxaline (see Kadin, S. B., Ger Offen., DE 2357186; 255 mg, 0.78 mmol), 4-(3-amino-propyl)-piperidine-1-carboxylic acid tert-butyl ester (see Egbertson, M, U.S. Pat. No. 5494921; 392 mg, 1.6 mmol) and potassium carbonate (220 mg, 1.6 mmol) was heated at 120° C. in DMSO (2 mL) for 17 h. After cooling to room temperature, the reaction mixture was diluted with EtOAc and washed with sat'd aq NaHCO3, sat'd aq NaCl, dried and concentrated under vacuum. The crude residue was chromatographed on SiO2-gel to give 150 mg of a yellow oil. API-MS: 533 (M+1). 1H NMR (300 MHz, CDCl3): d 7.75 (d, 1 H), 7.58 (d, 1 H), 7.35 (m), 7.15 (d, 1 H), 4.05 (m), 3.99 (s, 3 H), 3.97 (s, 3 H), 3.54 (bs, 1 H), 2.68 (t, 2 H),1.75 (m), 1.42 (s, 9 H), 1.1 (m).

Provenance & Evidence