Synthesis and mechanism of formation of novel 2,5-dihydro-2,5-diimino-3,4-di[(N,N-dimethylamino)methylideneamino]pyrroles and 5-amino-3,4-di[(N,N-dimethylamino)methylideneamino]-2H-2-iminopyrroles

Formation of 5-amino-3,4-di[(N,N-dimethylarnino)methylidenearnino]-2H-2-iminopyrroles 3 from the reaction of (Z)-N¹-(2-amino-1,2-dicyanovinyl)-N²-substituted-formamidines 1 with dimethylformamide diethyl acetal has been shown to occur by initial formation of (Z)-N¹-{l,2-dicyano-2-[N,N-dimethylamino)methylideneamino]vinyl}formamidines 8 (isolated), followed by base catalysed cyclisation and imi dazole ring opening by dimethyl amine. The kinetic product of the ring opening reaction is the 2,5-diimino2,5-dihydropyrrole derivatives 11, which have been isolated and characterized spectroscopically and by a single crystal X-ray analysis on the R = Ph derivative. In solution at room temperature the N-aryl derivatives undergo a rapid Dimroth rearrangement to give the thermodynamic ally more stable isomer 3 , but compound 11 (R = Me) is much more stable in solution.     

The mannich reaction in the synthesis of N,S-containing heterocycles 4. Aminomethylation of 6-amino-3,5-dicyano-1,4-dihydropyridine-2-thiolates: A convenient regioselective route to 3,5,7,11-tetraazatricyclo[7.3.1.02,7]tridec-2-ene derivatives

Treatment of N-methylmorpholinium 4-R-6-amino-3,5-dicyano-1,4-dihydropyridine-2-thiolates (R = 2-ClC₆H₄ and 2-MeOC₆H₄) with primary amines in the presence of an excess of formaldehyde gave 13-R-8-thioxo-3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-ene-1,9-dicarbonitrile derivatives in high yields (66–95%). In a similar way, aminomethylation of 3-R-10-amino-7,11-dicyano-9-aza-3-azoniaspiro[5.5]undeca-7,10-diene-8-thiolates (R = Me and Et) afforded 1′-alkyl-8-thioxospiro[3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-ene-13,4′-piperidine]-1,9-dicarbonitriles in 43–91% yields. Alternatively, these compounds were obtained by multicomponent cyclocondensation of N-alkylpiperidin-4-ones, cyanothioacetamide, primary amines, and aqueous formaldehyde. The starting 3-R-10-amino-7,11-dicyano-9-aza-3-azoniaspiro[5.5]undeca-7,10-diene-8-thiolates were prepared by a new method from N-alkylpiperidin-4-ones and cyanothioacetamide. The structure of 5,11-bis(4-ethoxyphenyl)-13-(2-methoxyphenyl)-8-thioxo-3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-ene-1,9-dicarbonitrile was examined by X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1014–1022, May, 2007.     

Synthesis and structure of novel 2-amino-l,3-dicyano-4-cyclopropyl-6-aryl-1,3-cyclohexadienes

The reaction of arylmethylenedicyanoacetates with 1,1-dicyano-2-cyclopropylpropene was studied and found to give 2-amino-1,3-dicyano-4-cyclopropyl-6-aryl-1,3-cyclohexadienes. The structure of 2-amino-6-(2-nitrophenyl)-1,3-dicyano-4-cyclopropyl-1,3-cyclohexadiene was corroborated by means of X-ray analysis.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 355–358, February, 1993.     

Ring transformations of 4H-pyrans. Pyridines from 2-amino-4H-pyrans

Ring transformations of 4H-pyrans into pyridines are reported. Treatment of 2-amino-4,6-diaryl-3,5-dicyano-4H-pyrans (I) with nitrosylsulfuric acid brings about their transformation into 3,5-dicyano-4,6-diaryl-2-pyridones (VI) which can also be obtained from α-benzoylcinnamonitriles (IX) and cyanoacetamide. Similarly, 2-amino-4,6-diaryl-5-carbethoxy-3-cyano-4H-pyrans (II) lead to 4,6-diaryl-5-carbethoxy-3-cyano-2-pyridones (VII). Treatment of both series of pyrans with sulfuric acid results in the formation of the corresponding 3,4-dihydro-2-pyridones (IV and V). Reaction of pyrans II with ammonium acetate in acetic acid yields 2-amino-4,6-diaryl-5-carbethoxy-3-cyanopyridines (XII). Pyrans I undergo an entirely different type of reaction upon treatment with this reagent leading to 2,4,6-triaryl-3,5-dicyano-1,4-dihydropyridines (XV).     

Synthesis and properties ofN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane-2-thiolate

The reaction of cyclopentylidenecyanothiocetamide with cyanothioacetamide andN-methylmorpholine gaveN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane-2-thiolate, which was used in the syntheses of substituted 2-alkylthiodihydropyridines and pyrazolodihydropyridine. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1849–1851, October. 1997.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. X. Synthesis of N,N-disubstituted 6-alkyl-4-amino-3,3-dichloro-3,4-dihydro-2H-pyran-2-ones and of 6-alkyl-4-amino-3-chloro-2H-pyran-2-ones

Cycloaddition of dichloroketene to N,N-disubstituted 1-amino-4-methyl-1-penten-3-ones and 1-amino-4,4-dimethyl-1-penten-3-ones occurred in moderate to fair yield only in the case of aromatic N-substitution to give N,N-disubstituted 6-alkyl-4-amino-3,3-dichloro-3,4-dihydro-2H-pyran-2-ones, which were dehydrochlorinated with DBN to afford in good yield N,N-disubstituted 6-alkyl-4-amino-3-chloro-2H-pyran-2-ones. In the case of aliphatic N,N-disubstitution, cyclo-addition led directly to 6-alkyl-4-dialkylamino-3-chloro-2H-pyran-2-ones only for N,N-disubstituted 1-amino-4,4-dimethyl-1-penten-3-ones. The reaction between 1-dimethylamino-4-methyl-1-penten-3-one and dichloroketene gave 3-chloro-4-dimethylamino-3,6-dihydro-6-isopropylidene-2H-pyran-2-one in low yield.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. XIX. Synthesis of N,N-disubstituted 4-amino-3-phenyl-2H-furo[2,3-h]-1-benzopyran-2-ones (4-amino-3-phenylangelicins). Crystal and molecular structure of 3-Phenylangelicin

1,4-Cycloaddition of phenylchloroketene to N,N-disubstituted 5-aminomethylene-6,7-dihydrobenzo[b]- furan-4(5H)-ones gave the corresponding adducts, namely N,N-disubstituted 4-amino-3-chloro-3,4,5,6-tetra- hydro-3-phenyl-2H-furo[2,3-h]-l-benzopyran-2-ones II , which were dehydrochlorinated with DBN to N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-furo[2,3-h]-1-benzopyran-2-ones III . Compounds III afforded the title compounds IV by dehydrogenation with DDQ. In the cycloaddition step, 3-phenylangelicin V , whose structure was confirmed by ¹H-nmr shift reagents data and by X-ray crystal structure determination, was almost always formed, probably starting from II by dehydrochlorination, dehydrogenation and hydrogenolysis of the disubstituted amino group. Separation of V was achieved by alumina chromatography either in the cycloaddition step or, in most cases, in the dehydrochlorination step. 3-Phenylangelicin crystallizes in the trigonal system, space group R3, with cell parameters (hexagonal axes) a = b = 41.021(10), c = 3.888(2) Å. The angelicin moiety forms a dihedral angle of 42.1(1)° with the phenyl substituent. Disordered solvent molecules of ethyl acetate are clathrated in channels in the direction of the crystallographic axis c.     

Reactions of 2-amino-, 2-alkylamino-, and 2-piperidino-1-azaazulenes with aryl and chlorosulfonyl isocyanates

Reaction of 2-amino-1-azaazulene with phenyl isocyanate gave 3-phenyl-2H-3,4-dihydro-1,3,4a-triazabenz[5,4-a]azulene-2,4-dione. Reactions of 2-alkylamino-1-azaazulenes with aryl isocyanates gave 2-(N-ethyl-N′-arylureido)-1-azaazulenes initially, which rearranged to N-aryl-2-alkylamino-1-azaazulene-3-carboxamides and successive reaction with another molar amount of aryl isocyanate furnished uracil-fuzed 1-azaazulenes. Reaction of 2-piperidino-1-azaazulene with aryl isocyanate gave N-aryl-2-piperidino-1-azaazulene-3-carboxamide. Reaction of 2-(substituted amino)-1-azaazulenes with chlorosulfonyl isocyanate gave 3-cyano- and 3-chloro-2-(substituted amino)-1-azaazulenes.     

On triazoles. V. Synthesis of 1- and 2-R1-3-R2,R3-amino-5-amino-1,2,4-triazoles

The correct isomeric and tautomeric structure of different 1- and 2-R¹-3-R²,R³-amino-5-amino-1,2,4-triazole derivatives prepared from the corresponding N-cyano-N'-R²,R³-S-methyl-isothioureas and the corresponding hydrazines was proved with the help of their ir, uv, ¹H-nmr and ¹³C-nmr spectra as well as the uv spectra of the Schiff bases of an isomeric pair.     

Reaction of 6-methoxybenzo[b]furan-3(2H)-one and benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes as a convenient synthetic route to substituted 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans and 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans

The reactions of 6-methoxybenzo[b]furan-3(2H)-one with 2-aryl-1,1-dicyanoethylenes and malononitrile or with aromatic aldehyde and two moles of malononitrile afford 2-amino-4-aryl-1,3-dicyano-7-methoxydibenzo[b,d]furans. The reactions of benzo[b]thiophen-3(2H)-one with 2-aryl-1,1-dicyanoethylenes or with aromatic aldehyde and one mole of malononitrile produce 2-amino-4-aryl-3-cyano-4H-benzothieno[3,2-b]pyrans.     

Syntheses and spectral properties of β-iodoureas and 2-amino-4,4-diphenyl-2-oxazolines

The syntheses of N-(trans-2-iodocyclohexyl)- 1–4 , N-(2-iodo-3,3-dimethylbutyl) 5 , and N-(2-iodo-1,1-diphenylethyl)ureas 6, 7 and the cyclization of 6 and 7 into 2-amino-2-oxazoline derivatives 8, 9 are reported. The structures of prepared compounds are based on analytical and spectroscopic data.     

Aminomethylation of N-methylmorpholinium 6-amino-4-aryl-3,5-dicyano-1,4-dihydropyridine-2-selenolates as an approach to the preparation of 3,5,7,11-tetraazatricyclo[7.3.1.02,7]tridec-2-ene-8-selenone derivatives

A reaction of N-methylmorpholinium 6-amino-4-aryl-3,5-dicyano-1,4-dihydropyridine-2-selenolates with primary amines and excess of formaldehyde leads to 3,5,7,11-tetraazatricyclo[7.3.1.0^2,7]tridec-2-ene-8-selenone derivatives. The same compounds were obtained by a multicomponent cascade cyclocondensation of benzaldehyde, cyanoselenoacetamide, primary amine, and excess of formaldehyde.     

Reaction of sulfene and dichloroketene with open-chain N,N-disubstituted α-aminomethyleneketones. Synthesis of N,N-disubstituted 4-amino-3,4-dihydro-(5-methyl-6-phenyl)(5,6-diphenyl)-1,2-oxathiin 2,2-dioxides and of 4-amino-3-chloro-5-methyl-6-phenyl-2H-pyran-2-ones

Cycloaddition of sulfene to N,N-disubstituted 3-amino-2-methyl-1-phenyl-2-propen-1-ones (I) and 3-amino-1,2-diphenyl-2-propen-1-ones (II) occurred in good to moderate yield only in the case of aliphatic N-substitution to give 4-dialkylamino-3,4-dihydro-(5-methyl-6-phenyl)(5,6-diphenyl)-1,2-oxathiin 2,2-dioxides. Polar 1,4-cycloaddition of dichloroketene to I and II occurred only in the former case, giving in good to moderate yield N,N-disubstituted 4-amino-3,3-dichloro-3,4-dihydro-5-methyl-6-phenyl-2H-pyran-2-ones which were dehydrochlorinated with DBN to N,N-disubstituted 4-amino-3-chloro-5-methyl-6-phenyl-2H-pyran-2-ones. In the reaction of 2-methyl-1-phenyl-3-diphenylamino-2-propen-1-one with dichloroketene, a product was isolated which was proven by uv, ir, nmr and chemical evidence to be the dipolar ion VI, the supposed intermediate of the polar 1,4-cycloaddition of dichloroketene to N,N-disubstituted enaminones.     

Multicomponent synthesis of 2-alkylthio-6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocycloalkanes. Molecular and crystal structure of 6-amino-2-(2-methylbenzylthio)-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane

2-Alkylthio-6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocycloalkanes were synthesized via the reaction of cycloalkylidene malononitriles with cyanothioacetamide and alkyl halides. The structure of 6-amino-2-(2-methylbenzylthio)-3,5-dicyano-1,4-dihydropyridine-4-spirocyclopentane was determined by the X-ray diffraction analysis.     

Synthesis,alkylation, and molecular and crystal structure ofN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclohexane-2-thiolate

The reaction of cyano(cyclohexylidene)thioacetamide with cyanothioacetamide or malononitrile andN-methylmorpholine yieldsN-methylmorpholinium 6-amino-3,5-dicyano-1,4-dihydropyridine-4-spirocyclohexane-2-thiolate. Its structure was established based on the results of alkylation and X-ray structural analysis.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2535–2540, October, 1996.     

Reaction of ketenes with N,N-disubstituted α-aminomethyleneketones. XII. Synthesis of N,N-disubstituted 4-amino-3-chloro-6-(2-methyl-l-propenyl) (2-phenylethenyl)-2H-pyran-2-ones

Cycloaddition of dichloroketene to N,N-disubstituted (E)-amino-5-methyl-1,4-hexadien-3-ones IV and (E,E)-1-amino-5-phenyl-1,4-pentadien-3-ones V occurred in moderate to good yield only in the case of aromatic N-substitution to give N,N-disubstituted 4-amino-3,3-dichloro-3,4-dihydro-6-(2-methyl-l-propenyl) (2-phenylethenyl)-2H-pyran-2-ones, which were dehydrochlorinated with DBN to afford in good yield N,N-disubstituted 4-amino-3-chloro-6-(2-methyl-propenyl)(2-phenylethenyl)-2H-pyran-2-ones. In the case of aliphatic N,N-disubstitution (dimethylamino group) of enaminones IV and V, the Cycloaddition led directly in low yield to 3-chloro-4-dimethylamino-6-(2-methyl-l-propenyl)(2-phenylethenyl)-2H-pyran-2-ones.     

Synthesis of 2-amino-4-imino-4,5-dihydrothiazoles from N-sulfonyl-α-chloroamidines and thiourea

A number of new and interesting 2-amino-4-(N-substituted)imino-4,5-dihydrothiazoles were synthesized by reacting thiourea (or thiourea hydrochloride) with N-alkyl- or N,N-dialkyl-N′-p-toluenesulfonyl-α-chloroacetamidines, where the N,N-alkyl groups were ethyl, cyclohexyl, benzyl, β-phenethyl, (3,5-dimethyl-1-adamantyl)-methyl, as well as N,N-dimethyl- and N,N-pentamethylene. Reactions of N-alkyl-N-p-toluenesulfonyl-2-chloroacetamidines (substituents being N-ethyl, N-benzyl and N,N-dimethyl) with thiourea hydrochloride in hot 2-propanol furnished 2-amino-4-(p-toluenesulfonyl)imino-4,5-dihydrothiazole (in 51, 60 and 65% yields, respectively) and the corresponding amine hydrochloride. In hot acetone or butanone, the reactions of these N-sulfonyl-2-chloroacetamidines with excess thiourea provided 2-amino-4-N-(alkyl or N,N-dialkyl)imminium-4,5-dihydrothiazole chlorides in 25–80% yield. The by-product from these reactions was p-toluenesulfonamide. The structures of the products were established by chemical transformations and spectral methods (nmr and mass spectra).     

P-N Compounds. 27. Synthesis of a 5-amino-4,6-dioxo-1,3,5,2-triazaphosphorine 2-oxide

Heating N⁴-phenylphosphinyl-bis-(N¹-dimethyl) semicarbazide in the presence, but not in the absence, of iodomethane gave 2-phenyl-5-dimethylamino-4,6-dioxo-1,3,5,2-triazaphosphorine 2-oxide and a mechanism for this reaction is proposed. The compound was also prepared by the addition of 1,1-dimethylhydrazine to phenylphosphonic diisocyanate. Treatment of the product with excess iodomethane gave a polymeric material and 1,1,1-trimethylhydrazinium iodides.     

Reactivity of 2-amino-1,3,4-thiadiazoles. Nucleophilic behaviour of some 2-amino-1,3,4-thiadiazoles: Model compounds

The ambident nucleophilic behaviour of some 2-amino-5-H-1,3,4-thiadiazoles in alkylation, acylation and nitrosation reaction has been verified. The structures assigned to the 2-amino-1,3,4-thiadiazoles ( 1a-i ) and to the Δ²-1,3,4-thiadiazolines ( 2a-e ) agree with the spectral data.     

Synthesis and properties of an energetic complex pentaamminecobalt (III) perchlorate,with 4-amino-1,2,4-triazole as ligand

Energetic metal complex, 4-amino-1,2,4-triazole-N¹(N²) pentaamminecobalt(III) perchlorate, was produced by the anation reaction of aqua pentaamminecobalt(III) perchlorate with 4-amino-1,2,4-triazole. The thermal decomposition of the metal complex and its mixtures with 1,1-diamino-2,2-dinitroethylene (FOX-7) was studied.