Trifluoroacetic acid → 2-(3,8-Diaza-bicyclo[4.2.0]oct-8-yl)-quinoxaline

Participants

Reaction Steps

To a solution of 8-quinoxalin-2-yl-3,8-diaza-bicyclo[4.2.0]octane-3-carboxylic acid tert-butyl ester (1.84 g, 5.40 mmol) in dioxane (30 mL) was added trifluoro acetic acid (8.0 mL). The reaction mixture was stirred at rt for 16 h. The solvent and excess trifluoro acetic acid were removed under reduced pressure. The crude product was purified on HPLC (Agilent, basic system) to yield the title compound (925 mg, 72%). MS (ESI) mass calcd. for C14H16N4, 240.3; m/z found, 241.2 [M+H]+. 1H NMR (CDCl3): 1H NMR (400 MHz, CDCl3) 8.12 (s, 1H), 7.86 (dd, J=8.4, 1.0, 1H), 7.67 (dd, J=8.4, 1.0, 1H), 7.54 (dd, J=8.4, 1.5, 1H), 7.37 (dd, J=8.3, 1.4, 1H), 4.45-4.37 (m, 1H), 4.17-4.03 (m, 1H), 3.90-3.82 (m, 1H), 3.57 (dd, J=14.3, 2.0, 1H), 3.19-3.04 (m, 2H), 2.98 (s, 1H), 2.81-2.62 (m, 2H), 2.14-2.03 (m, 1H), 1.85-1.73 (m, 1H).

Provenance & Evidence