Pinacol ester of 3-carboxyphenylboronic acid (1 mmol), 2-chloropyrimidine (1.5 eq.) and Cs2CO3 (4.4 eq.) were added to a degassed DMF:H2O (10:1 ratio, 0.3 M) solution under nitrogen atmosphere. The mixture was degassed once and then Pd(PPh3)4 (5% molar ratio) was added. The reaction mixture was heated to 110°C. After completion of the reaction, the solvent was removed under vacuum to give a dark colloidal residue. The residue was dissolved in EtOAc and H2O and then acidified with 2 M HCl to pH 2. The organic layer was separated and the aqueous layer was further extracted with EtOAc (2 times). The organic layers were combined, dried with MgSO4 and concentrated in vacuum to obtain the residue. The residue was dried in vacuum and subsequently purified by fast chromatography using 10-30% EtOAc/petroleum ether and 1% acetic acid as eluent to give the target compound 3-pyrimidin-2-yl-benzaldehyde. The compound was prepared as a white solid (79% yield) by Suzuki coupling reaction.1H NMR (400 MHz, DMSO-d6) δ 8.99 (t, J = 1.5Hz, 1H), 8.95 (d, J = 4.9Hz, 2H), 8.61 (d, J = 7.9Hz, 1H), 8.09 (d, J = 7.7Hz, 1H), and 7.68 (d, J = 7.8 Hz, 1H), 7.50 (t, J = 4.9 Hz, 1H).LCMS retention time 2.96 min, m/z 201.1 [M + H].
