Synthesis
The general procedure for the synthesis of methyl 3-(2-pyrrolyl)propionate from methyl (E)-3-(1H-pyrrol-2-yl)acrylate was as follows: methyl (E)-3-(1H-pyrrol-2-yl)acrylate (3.15 g, 21.1 mmol) was dissolved in methanol (160 mL) under argon protection. Palladium/carbon catalyst (246 mg, 10%) was added to the solution, followed by replacement of argon with hydrogen. The reaction mixture was stirred at room temperature until thin layer chromatography (TLC) analysis showed that the reaction was complete (about 16 hours). Upon completion of the reaction, the crude product was filtered through a bed of diatomaceous earth and the diatomaceous earth plug was washed with methanol (50 mL). The combined methanol washings were concentrated under vacuum to afford methyl 3-(2-pyrrolyl)propionate (3.13 g, 100%) as a light yellow oil, which did not require further purification. The nuclear magnetic resonance (NMR) data of the resulting product were consistent with those reported in the literature.1H NMR (CDCl3, 400 MHz) δ: 8.53 (1H, broad single peak), 6.69-6.68 (1H, multiple peaks), 6.13-6.10 (1H, multiple peaks), 5.94-5.93 (1H, multiple peaks), 3.71 (3H, single peak), 2.93 ( 2H, triple peak, J = 6.6Hz), 2.66 (2H, triple peak, J = 6.6Hz).13C NMR (CDCl3, 100MHz) δ: 174.5, 130.9, 116.8, 108.0, 105.5, 51.8, 34.4, 22.5.
References
[1] Tetrahedron, 2013, vol. 69, # 39, p. 8527 - 8533
[2] Chemistry - A European Journal, 2018, vol. 24, # 19, p. 4957 - 4966
[3] European Journal of Organic Chemistry, 2010, # 19, p. 3611 - 3620
[4] Journal of the American Chemical Society, 2017, vol. 139, # 44, p. 15801 - 15811
