Synthesis
GENERAL METHODS: Cyclohexanone (0.91 g, 10.0 mmol) was mixed with bis(trifluoromethanesulfonyl)imide salt ([(HSO3-p)2im][CF3SO3]) (0.5 mmol) in deionized water (15 mL), followed by the addition of p-chlorophenylhydrazine hydrochloride (1.44 g, 10.0 mmol). The reaction mixture was placed in a microwave reactor and stirred at 100 °C for about 15 min, and the reaction process was monitored by gas chromatography-mass spectrometry (GC-MS). After completion of the reaction, the mixture was cooled to room temperature and the precipitate was collected by filtration to afford 6-chloro-1,2,3,4-tetrahydrocarbazole. The mixed system of [(HSO3-p)2im][CF3SO3]/H2O used in the reaction can be directly recycled for subsequent reactions.
References
[1] Journal of Fluorine Chemistry, 2012, vol. 144, p. 45 - 50,6
[2] Tetrahedron Letters, 2018, vol. 59, # 22, p. 2145 - 2149
[3] Heterocyclic Communications, 2003, vol. 9, # 1, p. 9 - 12
[4] Organic and Biomolecular Chemistry, 2016, vol. 14, # 41, p. 9868 - 9873
[5] Patent: CN105968039, 2016, A. Location in patent: Paragraph 0049-0051