Synthesis
Methyl 5-bromo-2-chloropyridine-3-carboxylate is prepared by the reaction of 5-Bromo-2-chloronicotinic acid and Methanol. The specific synthesis steps are as follows:
To 0.5 L flask charged with 5-Bromo-2-chloronicotinic acid (25.0 g, 106.4 mmol) in MeOH (250 mL) was added H2SO4(5 mL). The mixture was heated to 60° C., stirred for 1.5 day. LC-MS indicated full conversion of starting material at this time. The reaction was cooled to RT and the volatile components removed in vacuo. The crude residue was dissolved in EtOAc (300 mL), quenched with sat. aqueous Na(HCO3)2(200 mL). The organic layer was separated, washed with brine, dried over MgSO4and concentrated to afford the compound, methyl-5-bromo-2-chloronicotinate, as a while solid (quantitative yield). LC-MS (M+H)=250.1.