Acetals of lactams and acid amides. 73. Synthesis and some properties of derivatives of 6-nitro-?-carboline

γ-Carbolines and their hydrogenated derivatives. 1. Aromatic γ-carbolines: methods of synthesis, chemical and biological properties (review)

“…Similar behavior is observed for tertiary amines, but metallation here is achieved by the action of lithium 2,2,6,6-tetramethylpiperidide (LTMP) [97]. Various 2H,5H-pyrido [4,3-b]indol-1-ones can be easily transformed into 1-chloro-5H-pyrido [4,3-b]indoles by the action of phosphorus oxychloride [41,98]. The oxidation of γ-carboline and its derivatives is accompanied by destruction of the benzene ring with the formation of a dicarboxylic acid, which on heating undergoes decarboxylation [99].…”

“…Depending on the temperature, Vilsmeier formylation of 2-cyanomethylindole leads to the formation of 2-(1-cyano-2-dimethylaminovinyl)-3-formyl-and 2-cyanomethyl-3-formyl-indoles, which in reaction with ammonia are converted into 4-cyano-and 3-amino-γ-carbolines respectively [38]. On the basis of the 2-(β-2-dimethylaminovinyl)indole derivative 11 it is possible to synthesize various 1-amino derivatives of 5-methyl-8-nitro-γ-carboline [41].…”

“…By nitrating 5-nitroso-γ-carboline it is possible to increase the content of the 6-nitro derivative substantially; this method was initially used for the nitration of carbazoles [90]. γ-Carbolines can be oxidized to 2-oxides by the action of m-chloroperbenzoic acid; the formation of the corresponding N-oxide was not observed [89] in the case of 30% aqueous hydrogen peroxide in acetic acid at 80°C, but with this oxidizing agent at 95°C 5-methyl-8-nitro-γ-carboline N-oxide was obtained with a yield of 85% [41]. Heating of γ-carboline 2-oxide with phosphorus oxychloride at 80-90°C leads to the formation of 1-chloro-γ-carboline, the chlorine in which can be substituted by a primary, secondary, or tertiary amino group.…”