N. S. Prostakov

Synthesis and transformations of 1-methyl-4-azafluorene

By means of catalytic dehydrocyclization of dimethyl-substituted 2-phenylpyridines in a pyridine ring to 1(2,3)methyl-4-azafluorenes with subsequent oxidation, synthesis of alkaloid onychine — 1-methyl-4-azafluorene — several of its isomers were achieved. Using 1-methyl-4-azafluorene, we obtained a C9 furfurylidene product, substituted tetrahydroindine[1,2-b]pyridine and NH-indine[1,2-b]-pyridine. We obtained 7-nitro-1-methyl-4azafluorene by nitration of onychine and oxidation of nitro-substituted azafluorene; this indicates an identical orientation of 4-azafluoren(one) and fluoren(one) during nitration.

Cyclopenta- and indenopyridine anhydrobases. A review

The preparation, structure, spectral characteristics, and chemical transformations of cyclopenta- and indenopyridine anhydrobases are reviewed.

SYNTHESIS OF 2-ALKYL(ARYL, HETARYL)-4-METHYL-1,2,3,4-TETRAHYDROQUINOLINES

We have developed a preparative, three stage of synthesis of substituted 1,2,3,4-tetrahydroquinolines. Treatment of N-aryl-imines with allylmagnesium bormide gave N-aryl-N-alkenylamines which were cyclized to the tetrahydroquinolines. The configurations and conformations of the 4-methyl-1,2,3,4-tetra-hydroquinolines containing different 2- substituents have been determined.

New method for the synthesis of pyrido[1,2-a]benzimidazole

A catalytic method for the conversion of α-(phenylamino)pyridines to pyrido-[1,2-a]benzimidazoles was developed.

Study of the stereochemistry of N-H and N-vinyl-4,5,7-trimethyi-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridines and their nitro derivatives by the method of 1H and 13C NMR

The configurations and conformational features of N-H and N-vinyl-4,5,7-trimethyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridines and their nitro derivatives were established by the method of 1H and 13C NMR spectroscopy. It was shown that the conformational uniformity of the piperideine ring in the compounds studied is strongly dependent on the character of the substituents in the pyrrole ring. A method for the determination of the orientation of the substituent at the α-position to the nitrogen atom of the piperideine ring, according to the direct 1JCH SSCC, was proposed.

SYNTHESIS, CHEMICAL-TRANSFORMATIONS AND STRUCTURE OF 1,2,3,4-TETRAHYDROSPIRO(QUINOLINE-2-CYCLOALKANES)

The cyclization of 1-(m-toluidino)-1-allylcyclohexane under acid-catalysis conditions gave 4,5- and 4,7-dimethyl-1,2,3,4-tetrahydrospiro(quinoline-2-cyclohexanes). The bromination, nitration, N-acylation, and N-allylation of 4-methyl-1,2,3,4-tetrahydrospiro[quinoline-2-cyclohexane(cyclopentane)] were studied. It was established that nitration takes place In the 6 and 7 positions, while bromination occurs in the 6 and 8 positions. The amino-Claisen rearrangement of N-allyltetrahydroquinolines is accompanied by quantitative allyl-vinyl isomerization. The stereochemistry of the synthesized spiro(tetrahydroquinolinecycloalkanes) was studied by PMR spectroscopy.

1-Methyl(benzyl)-2,5-dimethyl-4-N-[aryl(alkyl)amino]piperidines and their acyl derivatives

N-Substituted γ-aminopiperidines and their benz- and propioamides have been synthesized from γ-piperidones. The stereoisomeric amines and amides have been separated and identified.

Chemistry of 2-substituted benzimidazoles. 1. 5-Amino-2-methyl(aryl, arylalkyl, pyridyl)benzimidazoles

A series of 2-substituted benzimidazoles was synthesized. These products were consecutively converted into 5-nitro- and 5-amino-2-substituted benzimidazoles.

SYNTHESIS AND STRUCTURE OF 2-ARYL-2,4- DIMETHYL-1,2,3,4-TETRAHYDROQUINOLINES AND 1,3-DISUBSTITUTED INDENES

It has been shown that the intramolecular cyclization of N-(1-arylbutenyl)arylamines under acid catalysis conditions may proceed in two directions with the formation of 2-aryl-2,4-dimethyl-1,2,3,4-tetrahydroquinolines and 1,3 disubstituted indenes.

Synthesis and nitration of NH- and N-vinyl-4,5,7-trimethyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridines

It has been shown that the most efficient catalysts for the synthesis of 4,5,7-trimethyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridine from 1,2,5-trimethylpyridin-4-one and acetylene under Trofimov conditions are rubidium and potassium hydroxides. Use of Triton B or a mixture of trimethylbenzylammonium chloride with rubidium hydroxide as catalyst gives O-alkylated oxime. Their configurations and conformations were established through separation of the individual isomers of 1-vinyl-4,5,7-trimethyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridines. Acetyl nitrate nitration of the cis isomer of this compound gave the 2- and 3-nitro derivatives. Similar nitration of 4,5,7-trimethyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridine gave the 2-nitro-7-hydroxy derivative.