Reaction Steps
A 10-mL microwave vial was charged with tert-butyl 2-(4-chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-2-yl)-1H-pyrrole-1-carboxylate (0.138 g, 0.43 mmol), 4-aminophenyl acetic acid ethyl ester (0.093 g, 0.52 mmol), palladium acetate (0.005 g, 0.021 mmol), rac-BINAP (0.020 g, 0.032 mmol) and cesium carbonate (0.353 g, 1.08 mmol) in dioxane (4 mL) under argon. The reaction mixture was heated to 120° C. under microwave irradiation for 2 h. After this time, the reaction mixture was cooled, diluted with ethyl acetate (50 mL) then filtered through celite. The filtrate was washed with saturated sodium chloride (10 mL), dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated under reduced pressure. The residue was purified by chromatography on silica using dichloromethane/methanol (10:0 to 9:1) to afford an ˜4:1 mixture of tert-butyl 2-(4-((4-(2-ethoxy-2-oxoethyl)phenyl)amino)-6,7-dihydro-5H-cyclopenta[b]pyridin-2-yl)-1H-pyrrole-1-carboxylate as a brown oil (0.110 g, 55%). MW=461.55 1H NMR (CDCl3, 500 MHz) δ 7.30-7.22 (m, 3H), 7.16-7.13 (m, 2H), 6.93 (s, 1H), 6.30 (dd, J=3.0, 1.5 Hz, 1H), 6.16 (t, J=3.5 Hz, 1H), 5.67 (s, 1H), 4.15 (q, J=7.5 Hz, 2H), 3.58 (s, 2H), 3.03 (t, J=7.5 Hz, 2H), 2.82 (t, J=7.5 Hz, 2H), 2.18 (quin, J=7.5 Hz, 2H), 1.39 (s, 9H), 1.26 (t, J=7.5 Hz, 3H); ESI MS m/z 462 [M+H]+, and ethyl 2-(4-((2-(1H-pyrrol-2-yl)-6,7-dihydro-5H-cyclopenta[b]pyridin-4-yl)amino)phenyl)acetate. MW=361.44. 1H NMR (CDCl3, 500 MHz) δ 9.60 (br s, 1H), 7.30-7.27 (m, 2H), 7.18-7.14 (m, 2H), 7.10 (s, 1H), 6.84-6.81 (m, 1H), 6.51-6.48 (m, 1H), 6.23-6.20 (m, 1H), 5.67 (s, 1H), 4.18 (q, J=7.0 Hz, 2H), 3.61 (s, 2H), 2.98 (t, J=7.5 Hz, 2H), 2.78 (t, J=7.0 Hz, 2H), 2.17 (quin, J=7.5 Hz, 2H), 1.28 (t, J=7.0 Hz, 3H); ESI MS m/z 362 [M+H]+.
