Dimethylformamide → HCID 68286493, Verbindung

To a solution of Ethyl 4-amino-3,5-dibromothiophene-2-carboxylate (compound 34b, 5.0 g, 15.19 mmol) in DMF (25 ml) was added NaH (60% suspension in mineral oil) (1.82 g, 45.49 mmol) in portion wise manner at a temperature of about −5° C. The reaction mixture was then stirred at −5° C. for 20 min. To the reaction mixture was then added iodomethane (6.47 g, 2.83 ml, 45.59 mmol) and stirring was continued for 40 min at −5° C. The progress of the reaction was monitored by TLC. The reaction mixture was then quenched by addition of cold water (50 ml). the mixture so obtained was then extracted with ethyl acetate (3×100 ml). The combined organic layer was then dried over sodium sulphate and concentrated under reduced pressure to obtain a crude product, which was then purified by flash column chromatography using 2.5% ethyl acetate in hexanes as an eluent to obtain the title compound (3.2 g, 58.97%).