A versatile and efficient construction of the 6H-pyrido[4,3-b]carbazole ring system. Syntheses of the antitumor alkaloids ellipticine, 9-methoxyellipticine, and olivacine, and their analogs was written by Gribble, Gordon W.;Saulnier, Mark G.;Obaza-Nutaitis, Judy A.;Ketcha, Daniel M.. And the article was included in Journal of Organic Chemistry in 1992.SDS of cas: 5367-32-8 This article mentions the following:
A general and efficient synthesis of the 6H-pyrido[4,3-b]carbazole ring system is described, in which the key steps are (1) regioselective acylation of a 2-lithio-1-(phenylsulfonyl)indole with 3,4-pyridinedicarboxylic acid anhydride, (2) cyclization of the deprotected keto acid I to keto lactam II with acetic anhydride, and (3) the addition of methyllithium to give, after reduction of the intermediate diol III with sodium borohydride, the target ring system. In this fashion, ellipticine (IV, R = H), 9-methoxyellipticine (IV, R = MeO), and 9-hydroxyellipticine (IV, R = OH) were synthesized in excellent overall yields from indole. The use of Superhydride, in place of 1 equiv of methyllithium, provided a synthesis of olivacine and the use of phthalic anhydride in the sequence allowed for the preparation of 6,11-dimethylbenzo[b]carbazole. The overall yields of ellipticine (54%) and 9-methoxyellipticine (47%) in six steps from their resp. indoles represent one of the most efficient syntheses of these antitumor alkaloids. In the experiment, the researchers used many compounds, for example, 3-Methyl-4-nitroanisole (cas: 5367-32-8SDS of cas: 5367-32-8).
3-Methyl-4-nitroanisole (cas: 5367-32-8) belongs to ethers. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil. The unique properties of ethers (i.e., that they are strongly polar, with nonbonding electron pairs but no hydroxyl group) enhance the formation and use of many reagents. For example, Grignard reagents cannot form unless an ether is present to share its lone pair of electrons with the magnesium atom. Complexation of the magnesium atom stabilizes the Grignard reagent and helps to keep it in solution.SDS of cas: 5367-32-8
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem