2-(Tributylstannyl)pyridine → 1-[5-Benzyloxy-7-(2-pyridyl)-1,3-benzothiazol-2-yl]-3-ethyl-urea

Participants

Reaction Conditions

Reaction Steps

To a stirred of 1-(5-benzyloxy-7-bromo-1,3-benzothiazol-2-yl)-3-ethyl-urea (110 g, 0.27 mol) in DMF (1.1 L) was added 2-tributylstannyl pyridine (298 g, 0.81 mol). The resulting solution was purged with N2 for 15-20 min followed by addition of tetrakis(triphenylphosphine)palladium (0) (25.41 g, 0.022 mol). The resulting mixture was then heated to 100° C. under N2 atmosphere for 15-16 h. The reaction mass was cooled to 40-45° C. then filtered through celite. The celite bed was washed with DMF (500 mL) and hot EtOAc (1.50 L) and the combined filtrate concentrated at 60-70° C. under reduced pressure. The residue was purified through silica gel (20% EtOAc-Hexanes to 100% EtOAc) to obtain the desired product (76 g, 70%). 1H-NMR (DMSO-d6): δ 1.08 (t, J=7.20 Hz, 3H), 3.19 (q, J=6.80 Hz, 2H), 5.26 (s, 2H), 6.84 (br s, 1H), 7.32-7.43 (m, 5H), 7.51 (d, J=7.20 Hz, 2H), 7.69 (d, J=2.0 Hz, 1H), 7.95 (m, 1H), 8.25 (m, 1H), 8.78 (m, 1H) and 10.46 (br s, 1H). LCMS: 405.30 [M+H]+.

Provenance & Evidence