V. G. Zabrodnyaya

Reaction of phenylhydrazides of N-acyl-?-phenyl-?-alanine with phosphorus oxychloride

The reaction of N′-methyl-N′-phenylhydrazides of N-acyl-β-phenyl-β-alanine with phosphorus oxychloride is accompanied by cleavage of the C-N bond in the intermediately formed 2-aminoindole derivative and, after splitting out of an amide fragment, leads to 1-methyl-3-benzylidene-2-iminoindoline and nitriles. Pyrimido [4,5-b] indoles — products of cyclization of the corresponding intermediate 2-aminoindole derivatives — were isolated from the reaction mixtures in low yields. The structure of 1-methyl-3-benzylidene-2-iminoindoline was proved by alternative synthesis.

Synthesis of 2-amino-3-(?-aminoalkyl)indoles

Abstract2-Amino-3-(ω-phthalimidoalkyl)indoles have been obtained by the rearrangement of ω-phthalimido acid β-phenylhydrazides under the action of POCl3. The possibility has been studied of eliminating the phthalyl protective group from these compounds and a convenient method has been developed for obtaining 2-amino-3-(ω-aminoalkyl)indole dihydrochlorides. The behavior of the 2-amino-3-(ω-phthalimidoalkyl) indoles in alkylation reactions has been investigated.

Reaction of a 2-aminoindole with difunctional compounds

The reaction of a 2-aminoindole with arylidenemalonic and arylidenecyanoacetic esters was studied. The effect of substituents in the benzene ring of the arylidenemalonic ester on the reaction pathway is demonstrated.

Synthesis and antimicrobial activity of 2-amino-2-arylazoindole hydrochlorides

We synthesized the 2-amino-3-arylazoindoles by reacting 2-amino-l-methylindoles (I) with aryldiazonium salts. Electrophiiic substitution reactions among the 2-aminoindoles (bromination, nitration, and sulfonation) yield substitution products in position 3 [3]. Substitution occurs at position 5 of the benzene ring only in strongly acid media where 2aminoindole exists in the iminoindole tautomer form [3]. Under the reaction conditions we selected (acetate buffer solution pH 5.0), the reaction between the diazonium salts and the 2-amino-l-methylindoles I takes place more readily at position 3, which is more susceptible to electrophilic attack that results in the formation of the 2-amino-3-arylazoindoles llla-m.

meta-Substituted arylhydrazides in the Kost reaction

Kost cyclization of meta-substituted arylhydrazides results primarily in the formation of mixtures of 4- and 6-substituted 2-aminoindoles.

Synthesis of 10-phthalimidoalkyltetrahydropyrimido[1,2-a]-indoles

Abstract10-Phthalimidoalkyltetrahydropyrimido [1,2-a] indoles were obtained by rearrangement of cyclic hydrazides of N-phthalyl-ω-amino acids, viz., 1-phenyl-2-acyl-pyrazolidines, under the influence of phosphorus oxychloride.

Synthesis and reactions of 2-amino-3-(ω-chloroaklyl)indoles

The reaction of N-methyl-N-phenyl-N′-(ω-chloro)acylhydrazines with POC13 yields derivatives of 2-amino-3-(ω)-chloroalkyl) indoles. Hydrazides of β-chloropropionic acid were found to exist as the cyclic quaternary 3-oxopyrazolidinium salt. Several reactions involving the nucleophilic substitution of the chlorine atom in N-acylated derivatives of 2-aminoindole were studied.

Intramolecular cyclization of N-phthalyl-?-aryl-?-alanine phenylhydrazide

The reaction of N-phthalyl-β-aryl-β-alanine N′-methyl-N′-phenylhydrazides with phosphorus oxychloride (at∼80 °C) is accompanied by further transformations of the initially formed 2-aminoindole derivatives and leads to isoindolo[1′,2′∶2,3]-pyrimido[5,6-b]indole derivatives. Intermediate 2-aminoindoles were isolated at lower reaction temperatures. The hydrolysis of the isoindolo[1′,2′∶2,3]pyrimido [5, 6-b]indole derivatives was studied. The structures of the compounds obtained were established on the basis of the PMR, IR, and UV spectra and the results of elementary analysis.

Cyclization of 3-aryl-2-acylaminoindoles to benzo[c]-?-carbolines

Abstract3-Aryl-2-acylaminoindoles form a new heterocyclic system — benzo[c]-α-carbolines — under the conditions of the Bischler-Napieralski reaction.