Synthesis
Example 149a Synthesis of 2-methyl-1H-pyrrole-3-carboxylic acid: an aqueous solution (20 mL) of lithium hydroxide (1.563 g, 65.3 mmol) was added to a solution of dioxane (20 mL) containing ethyl 2-methyl-1H-pyrrole-3-carboxylate (2.0 g, 13.06 mmol). The reaction mixture was heated under reflux conditions for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature and subsequently extracted by partitioning with ethyl acetate and 1 M hydrochloric acid. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to afford the target compound 2-methyl-1H-pyrrole-3-carboxylic acid (1.513 g, 93% yield).
References
[1] Patent: US2014/275079, 2014, A1. Location in patent: Paragraph 0604
[2] Organic and Biomolecular Chemistry, 2015, vol. 13, # 29, p. 7911 - 7914
[3] Bioorganic and Medicinal Chemistry Letters, 2017, vol. 27, # 10, p. 2225 - 2233
[4] Chemische Berichte, 1911, vol. 44, p. 490
[5] Chemische Berichte, 1918, vol. 51, p. 569
