Synthesis
GENERAL STEPS: 7-Methylindole (20.0 g, 148 mmol) was dissolved in acetic acid (60 mL) and sodium cyanoborohydride (18.7 g, 296 mmol) was added slowly and in batches. The reaction mixture was stirred at room temperature for 2 hours. Upon completion of the reaction, the mixture was poured into 2 M NaOH aqueous solution (1500 mL). The aqueous phase was extracted with dichloromethane (CH2Cl2) and the organic layers were combined. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate (MgSO4) and concentrated under reduced pressure to give 7-methylindoline (20.0 g, 98% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 3.08 (2H, t, J = 8.4 Hz), 3.62 (2H, t, J = 8.4 Hz), 6.62-6.66 (1H, m), 6.78-6.83 (1H, m), 6.90 (1H, dd, J = 7.6, 0.4 Hz).
References
[1] Bioorganic and Medicinal Chemistry, 2014, vol. 22, # 5, p. 1649 - 1666
[2] Patent: US6162818, 2000, A
[3] Journal of Chemical Research, Miniprint, 1996, # 12, p. 2936 - 2945
[4] Chemical Communications, 2017, vol. 53, # 66, p. 9262 - 9264
[5] Journal of the American Chemical Society, 2015, vol. 137, # 36, p. 11718 - 11724
