To a stirred solution of diethyl 4-(6-methoxylbenzothiazol-2-yl)benzylphosphonate (0.10 g, 0.25 mmol) and 2-nitrobenzaldehyde (0.39 g, 0.25 mmol) in dry MeOH (10 ml) at 0° C. was added dropwise a solution of 0.5 M sodium methoxide (1.02 ml, 0.51 mmol). The reaction mixture was then allowed to rise to room temperature and heated under reflux for 18 h. The reaction mixture was cooled to room temperature and water (30 ml) was added followed by 1 M HCl until the reaction mixture became acidic. The reaction mixture was then extracted with DCM (3×80 ml) and the combined organic extracts washed with brine (50 ml) and dried (Na2SO4). The solvent was removed under reduced pressure to give a solid which was purified by flash chromatography (DCM) to give the title compound (0.043 g, 43%) as a yellow solid.
