Synthesis
General method: 5-methoxy-2-methyl-3-indoleacetic acid (1 eq.) was dissolved with BOP-Cl (1 eq.) in anhydrous CH2Cl2 (3 mL/mmol), triethylamine (2 eq.) was added, and the reaction was carried out for 5 min at room temperature. Subsequently, anhydrous methanol (0.14 mL/mmol) was added and stirred overnight at room temperature. After completion of the reaction, the reaction mixture was diluted with dichloromethane (12 mL/mmol), washed with water (2 x 6 mL/mmol), dried over anhydrous Na2SO4 and filtered. The filtrate was concentrated under reduced pressure, and the resulting crude product was purified by rapid chromatography on silica gel (gradient elution with ethyl acetate/hexane) to afford methyl 5-methoxy-2-methyl-1H-indole-3-acetate, which was initially a yellow viscous oil, and crystallized and solidified after inoculation and refrigeration.
References
[1] Tetrahedron, 2012, vol. 68, # 48, p. 10049 - 10058,10
[2] Tetrahedron, 2012, vol. 68, # 48, p. 10049 - 10058
[3] Bioorganic and Medicinal Chemistry, 2017, vol. 25, # 3, p. 1202 - 1218
[4] Bioorganic and Medicinal Chemistry, 2012, vol. 20, # 15, p. 4830 - 4837
[5] Journal of Medicinal Chemistry, 2007, vol. 50, # 8, p. 1810 - 1827
