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31st January 2013 @ 15:19
Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1<em>H</em>-pyrrole-3-carboxylate was synthesised with a yield of 7.7g, progressed to hydrolysis. === Reaction Start time: 11:00 AM EST 15/1/13 Potassium carbonate (11.2 g, 81 mmol, 1.3 equiv.) and sodium iodide (10.1 g, 68 mmol, 1.1 equiv. ) were stirred in acetonitrile (50 mL) and cooled in an ice bath. Ethyl acetoacetone (8.0 mL, 62 mmol, 1 equiv.) followed by chloroacetone (6.4 mL, 80 mmol, 1.3 equiv.) were added dropwise. The mixture was heated to 90 °C and left overnight. At 10:00 AM the next day, the mixture was filtered then concentrated under reduced pressure. The concentrated mixture was then washed with water (2 × 20 mL) and with brine (2 × 20 mL). The product was dried then concentrated under reduced atmosphere giving a brown oil (6.4 g) which was used in the second step without further purification. 4-fluoroaniline was added at 4:00 PM and the reaction was heated to 90 °C and left overnight. The reaction was cooled and dissolved with ethyl acetate (25 mL) then washed with water (2 × 20 mL), followed by brine (1 × 20 mL). The mixture was then concentrated under reduced pressure to give a brown liquid, which was recrystallised with EtOH (40 mL) and 40% EtOH (20 mL). Brown crystals formed (7.7 g, 29 mmol, 47% yield).   See also: [blog=3872]Synthesis of Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (MD 1-1)[/blog] [blog]1989[/blog] [blog]651[/blog] [blog]403[/blog]   Risk and Hazard Assessment: Same as [blog=3872]Synthesis of Ethyl 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carboxylate (MD 1-1)[/blog]