Sodium Bicarbonate → ethyl 2-(2-cyclohexyl-5-methyl-1H-pyrrol-1-yl)acetate

Temperature

55 °C

To a solution of 1-cyclohexylpentane-1,4-dione (1.32 g, 7.24 mmol) in dichloromethane (10 mL) was added ethyl 2-aminoacetate hydrochloride (1.01 g, 7.24 mmol) and solid sodium bicarbonate (1.52 g, 18.1 mmol). The reaction was heated at 55° C. for 6 hours, then stirred at 40° C. for an additional 14 hours, after which the reaction was nearly complete by LCMS analysis. The reaction mixture was cooled to room temperature, extracted with dichloromethane (3×50 mL), dried (sodium sulfate), filtered, and concentrated to a brown residue. Purification by silica gel column chromatography (Luknova 80 g, 20 mL/min) using 0 to 35% ethyl acetate in hexanes over 50 minutes afforded the product as a clear, colorless oil (1.45 g, 5.82 mmol, 80% yield). 1H NMR (400 MHz, CDCl3): δ (ppm) 5.86 (dd, 1H), 5.83 (d, 1H), 4.53 (s, 2H), 4.24 (q, 2H), 2.33 (m, 1H), 2.17 (d, 3H), 1.71-1.89 (m, 5H), 1.32-1.42 (m, 5H), 1.29 (t, 3H).

1. temperatureThe reaction mixture was cooled to room temperature
2. extractionextracted with dichloromethane (3×50 mL)
3. dry with materialdried (sodium sulfate)
4. filtrationfiltered
5. concentrationconcentrated to a brown residue
6. customPurification by silica gel column chromatography (Luknova 80 g, 20 mL/min)
7. customover 50 minutes

ORD record

ord-b4a383768f194e198d4718dbc4c4a441

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08674115B2