Synthesis
GENERAL STEPS: Example I Synthesis of 1-methyl-1H-indole-7-carbaldehyde
20 g of 1H-indole-7-carboxaldehyde was dissolved in 160 ml of N,N-dimethylformamide (DMF) and 15.5 g of potassium tert-butoxide was added in batches under argon protection. After addition, the reaction mixture was stirred for 20 min, followed by slow dropwise addition of 8.7 ml of iodomethane. After the dropwise addition, the reaction mixture was stirred at room temperature for 12 hours. After completion of the reaction, the mixture was partitioned between water and ethyl acetate. The aqueous phase was extracted twice with ethyl acetate. All organic phases were combined and washed with saturated aqueous sodium chloride solution. The organic phase was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to remove the solvent. The residue was recrystallized from water. The resulting solid was filtered by pumping and dried under vacuum. Yield: 20 g (91% yield). Mass spectrum (ESI+): m/z = 160 [M + H]+.
References
[1] Patent: US2011/269737, 2011, A1. Location in patent: Page/Page column 40
[2] Bioorganic and Medicinal Chemistry, 2014, vol. 22, # 7, p. 2060 - 2079
[3] Patent: WO2004/52890, 2004, A1. Location in patent: Page 92-93
[4] Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 15, p. 4533 - 4539
[5] Journal of Medicinal Chemistry, 2013, vol. 56, # 12, p. 5115 - 5129
