1-cyclopentylpentane-1,4-dione

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A slurry of ethyl 2-aminoacetate hydrochloride (2.93 g, 21.0 mmol), 1-cyclopentylpentane-1,4-dione (3.43 g, 20.4 mmol), and sodium bicarbonate (4.28 g, 51.0 mmol) in dichloromethane (20.4 mL) was heated at 50° C. for 72 hours, after which the reaction was diluted in water and extracted with dichloromethane (3×30 mL), dried (sodium sulfate), filtered and concentrated to a gold residue. Purification by silica gel chromatography (ISCO 120 g, 20 mL/min) using 0 to 35% ethyl acetate in hexanes afforded ethyl 2-(2-cyclopentyl-5-methyl-1H-pyrrol-1-yl)acetate (3.49 g, 14.8 mmol, 73% yield) as a clear colorless liquid. 1H NMR (400 MHz, CDCl3) δ (ppm): 5.84 (s, 2H, two shifts isochronous), 4.54 (s, 2H), 4.23 (q, 2H), 2.83 (m, 1H), 2.19 (s, 3H), 1.91-1.98 (m, 2H), 1.73-1.79 (m, 2H), 1.58-1.64 (m, 4H), 1.27 (t, 3H). extracted with dichloromethane (3×30 mL) dried (sodium sulfate) filtered concentrated to a gold residue Purification by silica gel chromatography (ISCO 120 g, 20 mL/min)