Uses
6-Cyanooxindole is a versatile chemical intermediate used in research and synthesis. It can act as a key core structure or intermediate in synthesizing new drug candidates.
[2]
Synthesis
General procedure for the synthesis of 2-oxo-2H-indole-6-carbonitrile from zinc cyanide and 6-bromo-2-indolone: Commercially available 6-bromo-2-indolone (656 mg), zinc cyanide (288 mg), and tetrakis(triphenylphosphine)palladium(0) (175 mg) were suspended in anhydrous N,N-dimethylformamide (6 mL). The resulting mixture was degassed by three argon pump/exhaust cycles and subsequently transferred to a preheated oil bath (80°C). After stirring the reaction mixture at a constant temperature for 15 h, it was cooled to room temperature, diluted with deionized water (60 mL) and extracted with ethyl acetate (3 x 60 mL). After combining the organic phases, it was washed with deionized water (2 x 60 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by fast column chromatography (silica gel, dichloromethane/methanol gradient elution) to afford the target product 2-oxo-2H-indole-6-carbonitrile (385 mg, 81% yield). Mass spectrometry analysis showed [M+H]+ peak of 159.
References
[1] Patent: US2006/173183, 2006, A1. Location in patent: Page/Page column 105
[2] Sumiyoshi, T., Tojo, K., Urabe, D., & Tobe, M. (2011). Asymmetric synthesis of the 6-cyanoindole derivatives as non-steroidal glucocorticoid receptor modulators using (+)- and (−)-tert-butyl 6-cyano-3-[3-ethoxy-1,1,1-trifluoro-2-hydroxy-3-oxopropan-2-yl]-1H-indole-1-carboxylate. Tetrahedron, Asymmetry, 22 2, Pages 153-160.
https://doi.org/10.1016/j.tetasy.2011.01.020
