Nitration of indoles. III. Polynitration of 2-alkylindoles was written by Noland, Wayland E.;Smith, Lowell R.;Rush, Kent R.. And the article was included in Journal of Organic Chemistry in 1965.Formula: C9H8N2O2 This article mentions the following:
Nitration in concentrated nitric acid of 2-methylindole and 1,2-dimethylindole gives the corresponding 3,6-dinitroindoles I and II; I was also obtained from 2-methylindole-3-carboxaldehyde and 2-methyl-6-nitroindole. 2-Methyl-3-nitroindole and 2-methyl-3H-indol-3-one oxime gives both I and 3,4-dinitro-2-methylindole (III); III was also obtained from 2-methyl-4-nitroindole (IV). Further nitration of I and II or their precursors gives the corresponding 3,4,6-trinitroindoles V and VI; 3-acetyl-2-methyl-4-nitroindole and IV also gave V. Nitration in concentrated nitric acid of 2-methyl-5-nitroindole (VI) and 1,2-dimethyl-5-nitroindole (VII) gives the corresponding 3,5-dinitroindoles VIII and IX. Further nitration of VIII and IX (or VII) gives the 3,5,6-trinitroindoles X and XI; X was also obtained from the 1-acetyl derivative or VI. Dimethylation of VIII gave 3,5-dinitro-2-ethyl-1-methylindole (XII), as proved by preparation from 2-ethylindole via the 5-nitro and 3,5-dinitro derivatives and methylation to XII. Nitration in concentrated sulfuric acid of 1,2,3-trimethylindole and 2,3,3-trimethyl-3H-indole gives the corresponding 5-nitro derivatives. The differing mechanisms of nitration of indoles in sulfuric acid and in nitric or acetic acids are discussed, and a set of orientation rules for nitration of 2-alkylindoles is presented. In the experiment, the researchers used many compounds, for example, 2-Methyl-6-nitro-1H-indole (cas: 3484-23-9Formula: C9H8N2O2).
2-Methyl-6-nitro-1H-indole (cas: 3484-23-9) belongs to indole derivatives. Indole could be stereoselectively alkylated with chiral cyclopentyl sulfone reagent. Due to this activity, the indole ring system has become an important component or intermediate in the synthesis of heterocycles.Formula: C9H8N2O2
Referemce:
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