Cesium carbonate → Ethyl 6-(3-ethylureido)-4-(phenylamino)nicotinate

Participants

Reaction Conditions

Reaction Steps

To a solution of ii (6.40 g, 23.18 mmol) in 1,4-dioxane (200 mL) was added N-ethylurea (2.60 g, 29.0 mmol) followed by Cs2CO3 (11.50 g, 34.80 mmol). The resulting solution was purged with nitrogen for 15 min followed by addition of Pd(OAc)2 (0.16 g, 0.70 mmol) and Xantphos (0.81 g, 1.40 mmol). The reaction mixture was again purged with nitrogen for 15 min and then heated at 80° C. for 16 h. The reaction mass was cooled to room temperature and filtered through a celite bed. The celite bed was washed with EtOAc and the combined filtrates concentrated under reduced pressure. Water was added to the residue and extracted with EtOAc (3×20 mL). The combined organic phase was washed with brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The crude residue was purified over silica gel (60-120 M, 50-75% EtOAc-hexane) to obtain a solid residue. This was purified further by trituration with 25% ether-hexane to afford compound iii as an off-white solid (7.0 g, 92%). 1H-NMR (400 MHz, DMSO-d6): δ 9.14 (s, 1H) and 9.64 (s, 1H), 8.61 (s, 1H), 7.70 (br s, 1H), 7.27-7.45 (m, 5H), 7.21 (t, J=7.20 Hz, 1H), 4.32 (q, J=7.20 Hz, 2H), 3.11 (m, 2H), 1.34 (t, J=7.20 Hz, 3H), 1.04 (t, J=7.20 Hz, 3H). [M+H]+ m/z=329.14.

Provenance & Evidence