Acetals of lactams and acid amides

It is shown that the alkylation of 1-methyl-6-cyano-1,2,3,4-tetrahydro-1, 8-naphthyrid-7-one under various conditions takes place at the oxygen atom of the oxo group in the 7 position. It was established by UV, IR, and mass spectroscopy that lactim-lactam tautomerism is observed in 6-dimethylamino-2-pyridone, pyrrolo[2,3-b] pyrid-6-one, 1,8-naphthyrid-7-one, and 8-oxopyrido [2,3-b] azepine derivatives. The tautomeric equilibrium constants (K_T) in various solvents were calculated. It is shown that the position of the equilibrium is shifted from the lactam to the lactim form when the polarity of the solvent decreases, when an electron-acceptor CN group is introduced, and when a 6-NR₂ group is included in the ring condensed with the pyridone ring.See [1] for communication XXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 793–797, June, 1977.     

Acetals of lactams and acid amides

Hydrogenated derivatives of indole, quinoline, and 1H,1-benzazepine were synthesized by reaction of 1-methyl-2-benzoylmethylenepyrrolidine, -piperidine, and -hexahydroazepine with acryloyl chloride. Alkylation of 1-methyl-5-oxo-8-benzoyl-1,2,3,4,5,6,7,8-octahydroquinoline with triethyloxonium tetrafluoroborate and subsequent treatment with sodium ethoxide gave the corresponding acetal, the reaction of which with substituted anilines gave 1-methyl-5-arylimino-8-benzoyl-1,2,3,4,5,6,7,8-octahydroquinolines. The IR and PMR spectra of the compounds are presented.See [1] for communication XIX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1348–1351, October, 1977.     

Acetals of lactams and acid amides

It is shown that acetals of acid amides and lactams undergo condensation at the -CH₃ (or CH₂) groups of enamino esters to give dienediamines, the cyclization of which led to benzene, pyridine, indole, quinoline, and benzazepine derivatives.See [1] for communication XXI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1518–1522, November, 1977.     

Acetals of lactams and acid amides

The reaction of acetals of amides and lactams with substituted 2-aminonicotinic acid esters was used to synthesize the corresponding amidines, which undergo cyclization to 1,8-naphthyridine derivatives when they are heated in the presence of acidic or basic catalysts and give pyrido[2,3-d]pyrimidine derivatives on reaction with amines.See [1] for communication XXVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1671–1676, December, 1978.     

Acetals of lactams and acid amides

The reaction of -cyano--dimethylaminocrotonic acid amide with acetals of dimethyl acetamide and N-methylbutyro-, -valero-, and -caprolactams gave enaminoacrylamidines, cyclization of which gave 3-cyano-6-dimethylamino-2-pyridone and the corresponding pyrrolo-,pyrido-, and azepino[2,3-b]pyridine derivatives.See [1] for communication XVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1106–1109, August, 1977.     

Acetals of lactams and acid amides

7-Dimethylamino-5-hydroxypyrido[2,3-d]pyrimidine and pyrrolo-, pyrido, and azepino [2,3-b]pyrido[2,3-d]pyrimidine derivatives were synthesized by reaction of acetals of amides and lactams with 4-amino-5-carbethoxypyrimidine derivatives and subsequent intramolecular cyclization of the intermediate amidines. The reactions of these compounds with phosphorus oxychloride and their alkylation reactions were studied.See [1] for communication XXVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1549–1554, November, 1978.     

Acetals of lactams and acid amides

The reaction of dimethylformamide diethylacetal with -cyano--dimethylaminoacrylamide proceeds at the NH₂ amide group to give the corresponding acylformamidine, from which 3-cyano-4-dimethylamino-2-pyridone was obtained by thermal cyclization. Pyrrolo-, pyrido-, and azepino-[3,2-c]pyridine derivatives were similarly synthesized from 1-methyl-2-(2-cyano-2-carbamido)-methylenepyrrolidine and the homologous six- and seven-membered enaminoamides.See [1] for communication XVII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1509–1512, November, 1976.     

Acetals of lactams and acid amides. 41. Enamino amides in the synthesis of pyrimidine derivatives

The reaction of -cyano--dimethylaminomethyleneacrylamide with arylamines was used to synthesize -cyano--arylaminoacrylamides, which react readily with dimethylformamide diethylacetal to give the corresponding N-dimethylaminomethylene derivatives. The latter undergo cyclization to 1-aryl-5-cyano-4-pyrimidinones when they are heated in dimethylformamide or acetic anhydride and to pyrimido-[5,4-c]quinolone derivatives when they are heated in glacial acetic acid.See [1] for communication 40.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 538–542, April, 1984.     

Acetals of amides and lactams in the synthesis of heterocyclic compounds

The review collects the results of investigations on the synthesis of heterocyclic compounds, mainly azaheterocycles, from amide and lactam acetals. The reasons for the high reactivity of these compounds with respect to nucleophilic and electrophilic reagents are considered, as are the principal pathways of heterocyclization of amidine and enamine systems synthesized via amide and lactam acetals.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 762–780, June, 1992.     

Acetals of lactams and acid amides. 53. Eamidines in the synthesis of pyridine and pyrimidine

The reaction of -cyano--aminocrotonic ester with DMFA diethylacetal gives 1-ethoxycarbonyl-1-cyano-2-(N-dimethylaminomethylene)-amino-4-dimethylaminobutadiene, the reaction of which with ammonium acetate and amines leads to 4-methylenepyrimidine derivatives. Condensation of -cyano--aminocrotonic ester with dimethylacetamide dieethylacetal gave 2-(ethoxycarbonylcyano)methylene-4-dimethylamino-6-methylpyridine. It was found that in an alkaline medium, 1-benzyl-4-(ethoxycarbonylcyano) methylenepyrimidine recyclizes into 1-benzyl-3-cyano-4-amino-2-pyridone.For Communication 52, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1109–1114, August, 1988.     

Acetals of lactams and acid amides. 60. Novel approach to the synthesis of γ-carbolines

N-Alkylation of 2-methyl-5-nitroindole followed by the Vilsmeyer reaction has given some 2-methyl-3-formyl-5-nitro-N-alkylindoles, which on reaction with DMF diethyl acetal afford 2-(-dimethylamino)vinylindoles. Heating the latter with ammonia provided a novel synthesis of -carbolines. Condensation of 1,2-dimethyl-3-formyl-5-nitroindole with dimethylacetamide diethyl acetal gave 2-dimethylamino-6-nitro-9-methylcarbazole.For Communication 59, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1483–1486, November, 1990.     

Acetals of lactams and acid amides. 34. Synthesis and properties of enamines of the isoquinoline series

The reactions of 1,2,3,4-tetrahydro-3-isoquinolone derivatives with dimethylformamide acetal and the hydrolysis and transamination of the resulting enamino amides — 1,2,3,4-tetrahydro-4-dimethylaminomethylene-3-isoquinolone derivatives — were studied. It is shown that 1,2,3,4-tetrahydro-1-phenyl-6,7-dimethoxy-3-isoquinolone can be converted to the corresponding lactim ether. The reactions of the latter with dimethylformamide acetal and hydrazine and the dehydrogenation of this lactim ether in the presence of sodium ethoxide were studied.See [1] for Communication 33.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 511–515, April, 1981.     

Acetals of lactams and acid amides. 33. Reaction of secondary enamino amides with amide acetals and synthesis of condensed pyrimidines

Condensed pyrimidines were synthesized by the reaction of dimethylformamide and dimethylacetamide diethylacetals with secondary enamino amides. It is shown that the piperido[1,2-c]pyrimidine derivative undergoes rearrangement to a 1,6-naphthyridine derivative under mild conditions.See [1] for communication 32.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1120–1124, August, 1980.     

Acetals of lactams and acid amides. 46. Unusual reactions of α-cyano-β-dimethylaminocrotonamide with anthranilic acid derivatives

It has been shown that the reaction of the enaminoamide -cyano--dimethylaminocrotonamide with anthranilic acid and its ethyl ester unexpectedly gives quinazoline-2,4-dione and 2-methyl-3-cyano-4-quinolone, respectively. The structures of the products were confirmed by their spectra and by direct synthesis.For communication 45, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 84–87, January, 1986.     

Acetals of lactams and acid amides. 35. Synthesis of condensed two- and three-ring pyridine systems on the basis of enamino amides

The synthesis of 2,3,5,6-tetrahydropyrrolo[3,2-c]pyrid-6-one was accomplished by rearrangement of 8H,1-cyano-8-dimethylaminomethylene-2,5,6,7-tetrahydropyrrolo[1, 2-c]pyrimidine. Pyrrolo[3,2-c]pyrimidine, 1,6-naphthyridine, and pyrimido[4,3-b]-azepine derivatives were synthesized on the basis of enamino dinitriles. The hydrolysis of 8H,1-cyano-8-dimethylaminomethylene-2,5,6,7-tetrahydropyrrolo[1,2-c]-pyrimidine in 50% CH₃COOH leads to a pyrrolo[1,2-c]pyrido[4,3-d]pyrimidine derivative. A similar dipyrido[4,3-d-1,2-c]pyrimidine derivative was obtained from 1-cyano-9-dimethylaminomethylene-2,5,6,7,8,9-hexahydropyrido[1,2-c]pyrimidine under these conditions, and 3,4-dioxo-3,4,7,8,9,10-hexahydropyrido[1,2-c]pyrano[4,3-d]-pyrimidine was synthesized bytreatment with a 1 N solution of HCl.See [1] for Communication 34.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 518–522, April, 1982.     

Acetals of lactams and acid amides. 54. New synthesis of pyrimido[4,5-f]pyrrolizines

A synthesis of pyrimido[4,5-f]pyrrolizine derivatives has been carried out, which is based on the intramolecular cyclization of 7-functionally substituted 6-amino-pyrrolizines with the participation of substituents in the 6- and 7-positions.For communication 53, see [1],Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 830–832, June, 1989.     

Acetals of lactams and amides. 44. Synthesis of derivatives of aminocyanopyridines from enamino amides and enamino nitriles

It has been established that in the reaction of a tertiary enamino amide with a primary amine a substantial influence is exerted by the basicity of the amine and the steric hindrance of its amino group. The secondary enamino amides obtained interact with the diethyl acetal of dimethylformamide to form enamino amides substituted at the amide nitrogen or 1-substituted pyramidin-4-ones, depending on the degree of steric hindrance of the NH group. Compounds of both these types, on being heated in an alkaline medium, are converted into derivatives of 4-amino-3-cyano-2-pyridone. An enamino dinitrile — -cyano--dimethylaminocrotonitrile — condenses with acetals of amides and lactams to form dienic diamines which can be converted into derivatives of 3-cyano-4-dimethylaminopyridine.For communication 43, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 646–649, May, 1985.     

Acetals of lactams and acid amides. 61. Synthesis and transamination of indoxyls and pyrrol-2-in-4-ones

Reaction of N-acetylindoxyl and 2-methyl-3-ethoxycarbonylpyrrol-2-in-4-one with acetals of N,N-dimethylformamide and N-formylpiperidine has given the enaminoketones. Hydrolysis and transamination of these enaminoketones has been studied. The structures of the products were established by IR, PMR, and ¹³C NMR spectroscopy.For Communication 60, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1487–1494, November, 1990.     

Acetals of lactams and acid amides. 67. Polarographic behavior of enamines of the indoles series in anhydrous DMF

The polarographic behavior of derivatives of 2-aminomethyleneindoxyl and 3-aminomethyleneoxindole in anhydrous DMF has been studied and the results compared with data on the polarographic reduction of substituted aminomethyleneacetophenones and of related enaminoketones and eneaminoamides. It is established that the ease of reduction is determined by the nature of the substituent on the enamine and indole nitrogen atoms and also by the presence or absence of an -methyl group in the -position of the eneamines (for noncyclic enaminoketones).For Communication 66, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 642–648, May, 1991.