Cyanoethylation of some n-substituted 2,5-dimethyl-4-piperidones

1,2,5-Trimetnyl- and 1-(-chlorocrotyl)-2,5-dimethyl-5-(-cyanoethyl)-4-piperidones were synthesized and separated into individual isomers. The corresponding isomeric 5-(-carboxyethyl)-4-piperidones were obtained by hydrolysis. The isomeric 1,2,5-trimethyl-3,5-bis(-cyanoethyl)- and 1,2,5-trimethyl-3,3,5-tris(-cyanoethyl)-4-piperidones were synthesized by subsequent cyanoethylation of the individual 1,2,5-trimethyl-5-(-cyanoethyl)-4-piperidone isomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–481, April, 1971.     

Synthesis of 1,2,5-trimethyl-4-ethoxycarbonylmethyl-4-hydroxypiperidine and its homologs

1,2,5-Trimethyl-4-ethoxycarbonylmethyl-4-hydroxypiperidine was obtained by the Reformatsky reaction between 1,2,5-trimethyl-4-piperidone and ethyl bromoacetate. Homologs were obtained from the same piperidone and ethyl -bromo--alkylacetates. Some further reactions of these hydroxypiperidines were studied.     

1,2,5-Trimethyl-4-(p-hydroxyaryl)-δ3-tetrahydropyridines and their spatial structure

The condensation of 1,2,5-trimethylpiperidine-4-one with phenol and isomeric cresols yields 1,2,5-trimethyl-4-(p-hydroxyphenyl)- and (p-hydroxytolyl)-³-tetrahydropyridines, the structure and conformation of which have been studied by proton NMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1367–1370, October, 1986.     

Schiff bases in syntheses of substituted naphthylamines,naphthyridines, azaphenanthrenes,and benzocarbazole

9-Methylnaphtho[2,1-b][1,6]naphthyrldine and 2,3-dimethyl-1-azaphenanthrene were obtained on a K-16 dehydrogenating catalyst from N-(1,2,5-trimethyl-4-piperidylidene)--naphthylamine, while N-cyclohexylidene--naphthylamine yielded N-phenyl--naphthylamine and benzo[a]carbazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1400–1403, October, 1972.     

Asymmetric synthesis and absolute configuration of 1-α-phenylethyl-2,5-dimethyl-4-piperidone isomers

Reaction of the methyl iodide of trans-1,2,5-trimethyl-4-piperidone with S--phenylethylamine proceeds asymmetrically and leads in 66% optical yield to the formation of the cis- and trans-diastereomeric pair of 1-(-phenylethyl)-2,5-dimethyl-4-piperidone, in which the new asymmetric centers possess the 2S,5S- and 2S,5R-configurations, respectively. According to x-ray structural analysis, the minor trans-1-(-phenylethyl)-2,5-dimethyl-4-piperidone component possesses the 2R,5S-configuration. The occurrence of asymmetric synthesis accompanying transamination was confirmed via the preparation of enantiomers of trans-2,5- and trans-1,2,5-trimethyl-4-piperidones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1641–1648, December, 1986.     

N-substituted 2, 5-dimethyl-4-ethynyl(vinyl)piperid-4-ols

They -isomers of 1-(3-chlorobuten-2-yl)- and 1-benzyl-2,5-dimethyl-4-ethynylpiperid-4-ols (I, II) and of 1-(3-chlorobuten-2-yl)-2,5-diemethyl-4-vinylpiperid-4-ol (III) and the quaternary salts of compounds I–III and of the -isomers of the 1,2,5-trimethyl-4-ethynyl-(vinyl)piperid-4-ols [1] have been synthesized.     

Reaction ofβ,β -dimethyldivinyl ketone with 2,5-dimethyl- and 1,2,5-trimethyl-4-piperidones

1-(3-Oxo-5-methyl-4-hexen-1-yl)-2,5-dimethyl-4-piperidone, 5-(3-oxo-5-methyl-4-hexen-1-yl)-2, 5-dimethyl-4-piperidone, and 5-(3-oxo-5-methyl-4-hexen-1-yl)-1,2,5-trimethyl-4-piperidone were synthesized. In the absence of a catalyst,-dimethyldivinyl ketone adds to 2,5-dimethyl-4-piperidone at the 1-position, while in the presence of alkali it adds at the 5-position.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–351, March, 1971.     

7,8,9-trimethyl-1-phenyl-3<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">d</Emphasis>][1,2,5]triazepin-4(5<Emphasis Type="Italic">H</Emphasis>)-one. Synthesis and reactions

A strategy was developed for the synthesis of 7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]-triazepin-4(5H)-one, reactions of its functionalization at the С⁴ atom and aza rings fusion at the С⁴?N³ bond were explored. The formation mechanism of the pyrrolo-1,2,5-triazepinone scaffold was suggested.     

Synthesis of aryl(γ-pyridyl)methanes and their conversion to substituted benzo[g]isoquinolines

New substituted pyridine bases of the aryl(-pyridyl)methane type were obtained from 1,2,5-trimethyl-4-piperidone by successive transformations. The new substituted pyridine bases were catalytically dehydrocyclized to di(tri)methylbenzo[g]isoquinolines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1077–1084, August, 1976.     

Di- and trimethyl-substituted 2-azafluorenes and dibasic acids of 2-azafluorenone

Dehydrocyclization of the corresponding 2,5-dimethyl-4-arylpyridines gave 3,5- and 3,8-dimethyl- and 3,5,7- and 3,5,8-trimethyl-2-azafluorenones. Dibasic acids of 2-azafluorenone were obtained from -carboxyarylcinchomeronic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1664–1667, December, 1972.     

1,4-bis(4′-hydroxy-1′,2′,5′-trimethyl-4-piperidyl)-1,3-butadiyne and its derivatives

1.4-Bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)-1.3-butadiyne has been synthesized from the individual isomers of 4-ethynyl-1,2,5-trimethyl-4-piperidol. Hydrogenation, bromination, and cleavage have given, respectively, 1,4-bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)butane, 1,4-bis(4-nydroxy-1,2,5-trimethyl-4-piperidyl)-1,2,3,4-tetrabromo-1, 3-butadiene, and 4-(1,3-butadiynyl)-1,2,5-trimethyl-4-piperidol.     

(1,2,5-Trimethyl-4-piperidylidene)-α-naphthylamines in the synthesis of 9-methylnaphtho [1, 2-b ] [1, 6 ]naphthyridine and 2,3-dimethyl-4- azaphenanthrene

9-Methylnaphtho[1,2-b][1,6]naphthyridine and 2,3-dimethyl-4-azaphenanthrene were obtained by the catalytic dehydrocyclization of (1,2,5-trimethyl-4-piperidylidene)--naphthylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 378–382, March, 1972.     

1H and 13C NMR spectra and three-dimensional structures of 1,2,5-trimethyl-4-phenylaminopiperidine isomers

The three-dimensional structures of two isomers of 1,2,5-trimethyl-4-phenylaminopiperidine were established on the basis of an analysis of their ¹H and ¹³C NMR spectra. The piperidine ring has a chair conformation in both isomers. The isomer has the 1,2e,5a, trimethyl-4e-phenylaminopiperidine structure, while the isomer has the 1,2e,5e-trimethyl-4e-phenylaminopiperidine structure.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1512–1515, November, 1982.     

1H and 13C NMR spectra,isomers, and imine-enamine tautomers of N-(1,2,5-trimethyl-4-piperidylidene)aniline

The product of condensing 1,2,5-trimethylpiperidin-4-one with aniline has been investigated by NMR spectroscopy. Three isomers of N-(1,2,5-trimethyl-4-piperidylidene)aniline have been identified differing in the configuration of the methyl groups at C₂ and C₅ of the piperidine ring and the Z,E isomerism about the C=N bond. Traces of the enamine tautomeric form of the imine were also detected. , , and spin-spin couplings were used to determine the structural configuration of the isomers.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1405–1408, October, 1989.     

The reaction of 3,4‐diamino‐1,2,5‐oxadiazoles with formaldehyde

The compounds 5,6‐dihydro‐4H‐imidazo[4,5‐c][1,2,5]oxadiazole ( 3a , R?H), 4,6,10,12‐tetramethyl‐5,6,11,12‐tetrahydro‐4H,10H‐bis(1,2,5)oxadiazolo[3,4‐d:3′,4′‐I][1,3,6,8]tetraazecine ( 4b , R?CH₃), N³,N³′‐methylenebis‐3,4‐diamino‐1,2,5‐oxadiazole ( 5a , R?H) and N³,N³′‐methylenebis(N,N′‐dimethyl‐3,4‐diamino‐1,2,5‐oxadiazolee) ( 5b , R?CH₃) were synthesized from the reaction of formaldehyde with 3,4‐diamino‐1,2,5‐oxadiazole and N,N′‐3,4‐dimethylamino‐1,2,5‐oxadiazole in an acetonitrile.     

Synthesis and structure of 1-benzoyl-2,5-dimethyl- and 1,2,5-trimethyl-4-arylpiperideins

Isomeric 1-benzoyl-2,5-dimethyl-³-piperidein and 1-benzoyl-2,5-dimethyl-⁴-piperidein were prepared from disubstituted -piperidols and were hydroxylated with osmium tetroxide. The isomeric 1,2,5-trimethyl-4-(p-nitrophenyl)-³- and-⁴-piperideins were obtained from trisubstituted -piperidols.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1200–1206, September, 1986.In conclusion, the authors would like to thank Yu. T. Struchkov and N. I. Lebedev for carrying out the x-ray structural study.     

Synthesis and three-dimensional structures of geometrical isomers of some 4-substitute d 1,2,5-trimethyl-4-acetoxy- and 1,2,5-trimethyl-4-benzoxypiperidines

Stereoisomers of the corresponding 4-substituted 1,2,5-trimethyl-4-acetoxy- and 1,2,5-trimethyl-4-benzoxypiperidines were obtained by acylation of the geometrical isomers of 1,2, 5-trimethyl-4-piperidol and its 4-ethynyl, 4-ethyl, and 4-phenyl-substituted derivatives. The preferred conformations of the investigated esters were elucidated by means of the PMR and IR spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.1, pp. 50–55, January, 1973.     

Synthesis of 3,9,9,9a-tetramethyl-1,2,3,9a-tetrahydro-9H-imidazo[1,2-<Emphasis Type="Italic">a</Emphasis>]-indol-2-ones by reaction of 2,3,3-trimethyl-3H-indole with 2-bromopropionamides

Alkylation of 2,3,3-trimethyl-3H-indole with 2-bromopropionamide and the subsequent treatment of the formed 1-(1-carbamoylethyl)-2,3,3-trimethyl-3H-indolium bromide with a base afforded 3,9,9,9a-tetramethyl-1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-one. Condensation of the 1-(1-carbamoylethyl)-2,3,3-trimethyl-3H-indolium salt with 2-hydroxy-1-naphthaldehyde gave a mixture of diastereomeric 1-(1-carbamoylethyl)spiro[2H-indole-2,3-[3H]naphtho[2,1-b]pyrans].Published in Khimiya Geterotsiklicheskikh Soedinenii, No 11, pp. 1690–1694, November, 2004.     

Indole derivatives

A mixture of isomeric 2,2,4-trimethyl- and 2,4,4-trimethyl-1,2,3,4-tetrahydro--carbolines is formed as a result of the Fischer cyclization of 2,2,6-trimethyl-4-piperidone arylhydrazones.See [1] for communication XXXVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1070–1073, August, 1971.     

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.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1375–1380, October, 1991.