Potassium Phosphate, Tribasic → 1-(5-(6-Bromopyridazin-4-yl)-7-(pyridin-2-yl)benzothiazol-2-yl)-3-ethylurea

Participants

Reaction Conditions

Reaction Steps

To a solution of 3,5-dibromopyridazine (0.32 g, 1.34 mmol) in DMF (5 mL) was added 2-(3-ethylureido)-7-(pyridin-2-yl)benzothiazol-5-ylboronic acid (0.46 g, 1.34 mmol) and aqueous solution of K3PO4 (0.43 g, 2.01 mmol). The reaction was degassed by purging N2 for 15 min followed by addition of bis(triphenylphosphine)palladium (II) chloride (0.11 g, 0.13 mmol). The reaction mixture was again degassed for 10-15 min then heated up to 80° C. for 2-3 h. After reaction completion (by TLC), the mixture was poured onto crushed ice and extracted with EtOAc (3×50 mL). The combined organics were washed with brine, dried over anhydrous Na2SO4, filtered and evaporated under reduced pressure. The crude residue was purified over 100-200 M silica-gel by using 3% MeOH-DCM to obtain the desired product as off-white solid (0.52 g, 85%). 1H NMR (DMSO-d6): δ 10.71 (s, 1H), 9.94 (m, 2H), 8.82 (m, 1H), 8.55 (d, J=8.0 Hz, 1H), 8.38 (s, 1H), 8.21 (s, 1H), 8.02 (t, J=8.0 Hz, 1H), 7.46 (m, 1H), 7.17 (br s, 1H), 3.22 (q, J=7.20 Hz, 2H), and 1.11 (t, J=7.20 Hz, 3H).

Provenance & Evidence