General procedure for the synthesis of 1-(1-methyl-1H-imidazol-5-yl)ethanone from the compound (CAS: 592554-79-5) and methylmagnesium bromide: First, the crude product (882) (14.2 mmol) was dissolved in tetrahydrofuran (THF) (100 mL). Methylmagnesium bromide (3 M solution in ether) (22.2 mL) was slowly added under cooling conditions in an ice bath, the titration was controlled to be completed within 10 min and the reaction was carried out under nitrogen (N2) protection. Subsequently, the reaction mixture was warmed up to 40 °C and stirred continuously for 4 h or until the reaction was complete. After completion of the reaction, it was again cooled in an ice bath and the reaction was quenched by slow addition of saturated ammonium chloride (NH4Cl) solution. Initial extraction was carried out with ethyl acetate followed by three extractions with dichloromethane (CH2Cl2). The organic phases were combined, dried with anhydrous magnesium sulfate, filtered and the solvent evaporated. Finally, the product was stored under vacuum to afford crystalline 1-(1-methyl-1H-imidazol-5-yl)ethanone (883) (1.78 g, 74% yield).
