Dimethylformamide → Ethyl 1-(4-bromo-2-methylphenylaminocarbonyl)cyclopropanecarboxylate

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Reaction Steps

Into a 50 milliliter three-necked round-bottom reaction flask equipped with a mechanical stirrer, thermometer and nitrogen inlet and outlet was added 5.0 grams (17.0 mmol) of ethyl 3-[(4-bromo-2-methylphenyl)amino]-3-oxopropanoate, 3.91 grams (16.7 mmol) of 2-chloroethyl-paratoluenesulfonate, 5.74 grams (41.6 mmol) of anhydrous potassium carbonate and 17 milliliters of anhydrous dimethylformamide. The resulting mixture was stirred at ambient temperature under a nitrogen atmosphere for a period of 4 days. The product was then isolated by diluting with methylene chloride, filtering off the solids and concentrating under reduced pressure to give a solid material. Chromatography on silica gel with a 3:1 volume/volume hexane-ethyl acetate eluent provided 1.89 grams (5.8 mmol) of ethyl 1-(4-bromo-2-methylphenylaminocarbonyl)cyclopropanecarboxylate as a white solid having a melting point of 87.5° C.-89.0° C. The total yield was 35 percent based on a 96.7 weight percent assay of the staring ethyl 3-[(4-bromo-2-methylphenyl)amino]-3-oxopropanoate. NMR analysis of the product indicated the following:

Provenance & Evidence