GENERAL METHODS: To a solution of methanol (0.7 mmol) and AlCl3 (0.7 mmol) in toluene (10 mL) was added compound 3 (CAS:1202680-24-7, 0.7 mmol). The progress of the reaction was monitored by thin layer chromatography (TLC) and the mixture was stirred at room temperature until the compound 3 was completely consumed. Upon completion of the reaction, 10% NaOH aqueous solution (50 mL) and dichloromethane (30 mL) were added to the reaction mixture under stirring for extraction. The organic layer was separated and washed with distilled water (50 mL) and subsequently dried over anhydrous magnesium sulfate. The solvent was removed by evaporation under reduced pressure to give the crude product. The crude product was purified by passing through an open silica gel column (2.5 x 4 cm) using hexane/ethyl acetate (3:1, v/v) as eluent. Compounds 5 and 6 were eluted first, followed by ethyl acetate. Finally, 4,5-dichloropyridazin-3(2H)-one (1) was eluted. The column chromatography fractions containing the pure compounds were combined and the solvents were evaporated under reduced pressure to afford the target product, methyl phenyl carbonate.4,5-Dichloropyridazin-3(2H)-one was obtained in quantitative yield and was reusable.
