Synthesis of new photochromic compounds from the dimer of arylphenanthroimidazoles

Treatment of the dimer of 2-arylphenanthro[9,10-d]imidazoles with nucleophilic compounds such as alcohols, aliphatic amines, and carboxylic acids afforded 2-substituted-2H- and 4-substituted-4H-2-arylphenanthro[9,10-d]isoimidazoles. These products showed a characteristic photochromism by dissociation to a stable imidazolyl radical.     

Photocyclization of 2-[1]benzothien-3-yl)-3-phenylpropenoic acids

Photocyclization of the substituted 2-([1]benzothien-3-yl)-3-phenylpropenoic acids 3a-c in the presence of iodine and air in a benzene-cyclohexane mixture afforded a separable mixture of three compounds, benzo[b]naphtho[2,1-d]thiophene-6-carboxylic acids 4a-c , 6H-benzo[b]naphtho[2,3-d]thiopyran-6-ones 5a-c , and 10-methoxy-2-methyl-6H-benzo[b]naphtho[2,3-d]pyran-6-one ( 6 ).     

Synthesis and Transformations of 5-Substituted 2-Aryl-7H-[1,2,4]triazolo[3,2-b][1,3]thiazin-7-ones and 2-Aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones

3-Aryl-1,2,4-triazole-5-thiones react with dimethyl acetylenedicarboxylate and methyl 3-phenyl-propynoate to afford the corresponding 5-substituted 2-aryl-7H-[1,2,4]triazolo[3,2-b][1,3]thiazin-7-ones. Treatment of 2-aryl-2,3-dihydro-4H-[1,3]thiazino[3,2-a]benzimidazol-4-ones with alkalies leads to formation of 3-(benzimidazol-2-ylsulfanyl)-3-arylpropionic acids, their reaction with methyl p-toluenesulfonate yields 1-(3-methyl-2-thioxo-2,3-dihydro-1N-benzimidazol-1-yl)-3-phenyl-2-propen-1-one, and oxidation with hydrogen peroxide gives benzimidazole-2-sulfonic acid and 3-aryl-2-propenoic acids.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 109–114.Original Russian Text Copyright © 2005 by Britsun, Esipenko, Chernega, Lozinskii.     

Synthesis of 1H-thieno[3,4-c]pyrazoles,thieno[3,4-b]furans,selenolo[3,4-b]furans and pyrrolo[3,4-d]thiazoles

Starting from the readily available aryl 2-methyl-5-phenyl-3-furyl ketones, 5-methyl-1H-1-phenylpyrazole-4-yl ketones and 4-methyl-2-phenyl-5-thiazolylcarboxaldehyde, a series of 2-phenyl-4-arylthieno[3,4-b]-furan, 2-phenyl-4-(p-methoxyphenyl)selenolo[3,4-b]furan, 4-aryl-1H-1-phenylthieno[3,4-c]pyrazole and 5-benzyl-2-phenylpyrrolo[3,4-d]thiazole were prepared in high yield.     

Phenanthro-imidazole

Zusammenfassung Es wird die Synthese verschiedener Chlor-, Brom- und Nitro-1H-Phenanthro[9,10-d]imidazole beschrieben.

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The synthesis of several chloro-, bromo-, and nitro-1H-Phenathro[9,10-d]imidazoles is described.

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Herrn Professor Dr.F. Wessely zum 70. Geburtstag in Verehrung gewidmet.     

1, 3-dipolar cycloaddition of diazomethane to azolopyridazines. The synthesis of 8-methyl-8H- and 9-methyl-9H-pyrazolo[3, 4-d]-s-triazolo[4, 3-b]pyridazine and 1-methyl-1H- and 2-methyl-2H-imidazo[1, 2-b]pyrazolo[3, 4-b]pyridazine derivatives

The transformations of 7-methyl-7H- and 8-methyl-8H-pyrazolo[4, 3-d]tetrazolo[1, 5-b]pyridazines 1, 2, 9 and 10 into 8-methyl-8H- and 9-methyl-9H-pyrazolo[3, 4-H]-s-triazolo[4, 3-b]pyridazines 7 and 8 , and 1-methyl-1H-and 2-methyl-2H-imidazo[1, 2-b]pyrazolo[3, 4-d]pyridazines 13 and 14 are described.     

Synthesis and Properties of 2-(2-Furyl)- and 2-(2-Thienyl)-1-methylphenanthro[9,10-d]imidazoles

Condensation of 9,10-phenanthrenequinone with 2-furaldehyde and 2-thiophenecarbaldehyde in glacial acetic acid in the presence of ammonium acetate gave 2-(2-furyl)- and 2-(2-thienyl)phenanthro[9,10-d]imidazoles which were converted into the corresponding 1-methyl derivatives. The furan and thiophene rings in the products lose their acidophobic properties. Depending on the conditions, electrophilic substitution reactions in 2-(2-furyl)- and 2-(2-thienyl)phenanthro[9,10-d]imidazoles occur both at the furan (thiophene) and phenanthrene moieties.     

Oxidation products of 2-arylphenanthro-[9,10-d]imidazoles—II : Structure and photochromism of oxidation products of 2-(4-methoxyphenyl)-phenanthro-[9,10-d]imidazole

By ferricyanide oxidation of 2-(4-methoxyphenyl)phenanthro[9,10-d]imidazole, three new photochromic compounds were obtained. These were 4-ethoxy-4H-, 4-methoxy-4H- and 2-methoxy-2H-phenanthro[9,10-d]imidazoles. These compounds gave the 2-(4-methoxyphenyl)-phenanthro[9,10-d]imidazolyl radical and acetaldehyde or formaldehyde by light irradiation. The imidazolyl radical dimerized gradually in the dark and the dimer dissociated to the imidazolyl radical on heating.     

The reaction of 2-amino-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]-pyrimidine with carbon disulfide and alkylation of its products

In the reaction with carbon disulfide, 2-amino-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine (1) forms the alkaline salts of substituted dithiocarbamic or iminodithiocarbonic acids depending on the molar ratio between1, CS₂, and the alkali. The alkylation of these salts leads to the esters ofN-(7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine-2-yl)dithiocarbamic (2) and diesters of (7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine-2-yl)iminodithiocarbonic acids (3). The synthesis of asymmetric diesters3 may be fulfilled based on monoesters2.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 14–14, August, 1994.     

New polyheterocyclic series based on 4,5,6,7-tetrahydrothieno[2,3-c]pyridine

4,8-Dimethyl-6,7,8,9-tetrahydropyrido[4′,3′:4,5]thieno[2,3-e][1,2,4]triazolo[3,4-a]-4H-pyrimidin-5-ones, 7-methyl-2,3,6,7,8,9-hexahydropyrido[4′,3′:4,5]thieno[2,3-d]pyrrolo[1,2-a]-1H, 10H-pyrimidin-10-one, 8-methyl-1,2,3,4,7,8,9,10-octahydropyrido[4′,3′:4,5]thieno[2,3-d]-11H-pyrimidin-11-one, and 9-methyl-2,3,4,5,8,9,10,11-octahydro[4′,3′:4,5]thieno[2,3-d]azepino-[1,2-a]-1H, 12H-pyrimidin-12-one which consist four new heterocyclic ring systems were synthesized from 2-amino-3-carbethoxy-5-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine.     

Reactions with diazoazoles. Part VI. Unequivocal synthesis of 3-methyl-3h-azolotetrazoles. Correction of the formerly described 3-methylazolotetrazoles in favour of mesoionic 2-methylazolotetrazoles

3-Methyl-3H-pyrazolo[1,5-d]tetrazoles 2 and 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) have been unequivocally synthesized by annulation of the tetrazole moiety to the pyrazole resp. 1,2,4-triazole system. The constitution of some N-methyl substituted azolotetrazoles, formerly described as 3-methyl-3H-pyrazolo[1,5-d]tetrazoles 2, 3-methyl-6-phenyl-3H-1,2,4-triazolo[1,5-d]tetrazole (4) and 1-methyl-6-phenyl-1H-1,2,4-triazolo[4,3-d]tetrazole (5), has to be revised in favour of the corresponding mesoionic 2-methyl derivatives 2′, 4′, 5′. The structures of 3-methyl-3H- as well as of 2-methyl-2H-pyrazolo[1,5-d]tetrazole derivatives 2a, 2c, 2′a have been determined by X-ray analyses. The azapentalenic system is aromatic in all three measured compounds and mesoionic in the case of the 2-methyl-2H- substitution pattern. The phenyl and ester substituents are coplanar with the azapentalene system. 3-, 2-, and 1-Methylpyrazolo[1,5-d]tetrazoles exhibit different behaviour when allowed to react with stannous chloride or sodium ethoxide. Azolotetrazoles with a methyl substituent at N-1, N-2 or N-3 of the tetrazole moiety can be distinguished by a combination of ¹H and ¹³C nmr with respect to the chemical shifts of the N-methyl group and the bridgehead carbon. Results of semiempirical calculations of the pyrazolo[1,5-d]tetrazole anion and of its N-methyl derivatives are discussed.     

Synthesis of new imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-one derivatives by iodocyclization of 6-alkenyl(alkynyl)-aminopyrazolo[3,4-d]pyrimidin-4(5H)-ones

6-Allyl(diallyl, prop-2-yn-1-yl)amino-1-R-pyrazolo[3,4-d]pyrimidin-4(5H)-ones reacted with iodine to give angularly fused 8-iodomethyl-7,8-dihydro-1-R-imidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-ones which were treated with sodium acetate to obtain 8-methylidene-1-R-7,8-dihydroimidazo[1,2-a]pyrazolo-[4,3-e]pyrimidin-4(6H)-ones as a result of elimination of hydrogen iodide. 8-Methylidene-1-R-7,8-dihydroimidazo[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-ones were converted into 8-methyl-1-R-imidazo[1,2-a]pyrazolo-[4,3-e]pyrimidin-4(5H)-ones on heating to the melting point. 8-Methylidene-1-phenyl-7,8-dihydroimidazo-[1,2-a]pyrazolo[4,3-e]pyrimidin-4(6H)-one underwent isomerization into linearly fused 6-methyl-1-phenyl-1,8-dihydro-4H-imidazo[1,2-a]pyrazolo[3,4-d]pyrimidin-4-one on heating in sulfuric acid.     

N-Amino Derivatives of Condensed Imidazole Systems

The previously unknown 1-amino- and 3-aminonaphtho[1,2-d]imidazoles, 1-aminonaphtho[2,3-d]imidazole, 1-aminophenanthro[9,10-d]imidazole and the N-amino-N'-methylimidazolium picrates corresponding to them have been obtained by direct amination of a series of condensed imidazoles with O-picrylhydroxylamine. An X-ray structural investigation of 1-amino-3-methylnaphtho[1,2-d]imidazolium picrate showed that, in difference to 1-aminobenzimidazolium salts, a conformation exists in it in which the hydrogen atoms of the N-NH₂ group are directed to the side of the meso carbon atom.     

Synthesis and selected transformations of 1-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)ethanones and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl]ethanones

By cycloaddition of arylazides to acetylacetone are obtained derivatives of 1,2,3-triazole. In the reaction of 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) and 1-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] ethanones (VIIa-VIIe) with isatin are obtained 2-[1-(R-phenyl)-5-methyl-1H-1,2,3-triazol-4-yl]-4-quinolinecarboxylic acids (IIIa–IIIe) and 2-[4-(4-R-5-methyl-1H-1,2,3-triazol-1-yl)phenyl] -4-quinolinecarboxylic acids (IXa, IXb), respectively. We found that 1-[5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] ethanones (IIa–IIe) readily transform into [5-methyl-1-(R-phenyl)-1H-1,2,3-triazol-4-yl] acetic acids (IVa–IVc) by the method of Wilgerodt-Kindler. The (5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)acetic acid reacts with 5-phenyl-4-amino-4H-1,2,4-triazol-3-thiol affording 6-[(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl) methyl]-3-phenyl[1,2,4] triazolo[3,4-b] [1,3,4] thiadiazole (VI). Original Russian Text ? N.T. Pokhodylo, R.D. Savka, V.S. Matiichuk, N.D. Obushak, 2009, published in Zhurnal Obshchei Khimii, 2009, vol. 79, no. 2, pp. 320–325.     

New Strategy of the Synthesis of 3,4-Dihydropyrimido[1,2-<Emphasis Type="Italic">a</Emphasis>]benzimidazol-2(1<Emphasis Type="Italic">H</Emphasis>)-ones

A new procedure has been developed for preparative synthesis of 3,4-dihydropyrimido[1,2-a]-benzimidazol-2(1H)-ones by thermal intramolecular heterocyclization of 3-[2-(propylsulfanyl)- and 2-(benzylsulfanyl)-1H-benzimidazol-1-yl]propanehydrazides and 3-[2-(benzylsulfanyl)-1H-benzimidazol-1-yl]-propanamide.     

Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives

Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methyl[2]benzopyrano[4,3-c]pyrazol-5-one (yield 10%), 1,4-dimethyl-3-phenylpyrazolo[3,4-c]isoquinolin-5-one (yield 10%), N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-hydroxybenzamide (yield 8%) and 4′-hydroxy-2,3′-dimethyl-1′-phenylspiro[isoindoline-1,5′-[2]-pyrazolin]-3-one (yield 20%). Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenylpyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]-diazocin-10-(9H)one (yield 8%), 4-methyl-1,3-diphenylpyrazolo[3,4-c]isoquinolin-5-one (yield 7%) and 4′-hydroxy-2-methyl-1′,3′-diphenylspiro[isoindoline-1,5′-[2]pyrazolin]3-one (yield 10%). The spiro compounds 6a,b underwent thermal and acid-catalysed conversion into the hitherto unknown 2-benzopyrano[4,3-c]pyrazole ring system 7a,b in good yield. Analytical and spectral data are presented which supported the structures proposed.     

A new method for the synthesis of novel 1-aryl-3-heteroaryl-1H-pyrazolo[3,4-b]quinoxalines

The reaction of 3-(2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-ylmethylene)-2-oxo-1,2,3,4-tetrahydroquinoxaline 4 with o-chlorobenzenediazonium chloride gave 3-[α-(o-chlorophenylhydrazono)-2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-ylmethyl]-2-oxo-1,2-dihydroquinoxaline 6 , whose refluxing in phosphoryl chloride/pyridine afforded 1-(o-chlorophenyl)-3-(2,3-dihydro-4-methyl-3-thioxo-4H-1,2,4-triazol-5-yl)-1H-pyrazolo[3,4-b]quinoxaline 7. The reactions of 6 and 7 with nitrous acid resulted in sulfur extrusion to provide 1-(o-chlorophenyl)-3-(4-methyl-4H-1,2,4-triazol-5-yl)1H-pyrazolo[3,4-b]quinoxaline 8 and 3-[α-(o-chlorophenylhydrazono)-4-methyl-4H-1,2,4-triazol-5-ylraethyl]-2-oxo-1,2-dihydroquinoxaline 9 , respectively.     

Synthesis of 2-hetaryl-6H-pyrazolo[3,4-d]-1,2,3-triazoles

A novel efficient synthesis of 2-hetaryl-4-methyl-6-phenyl-6H-pyrazolo[3,4-d]-1,2,3-triazoles was achieved by the reaction of 5-amino-3-methyl-4-nitroso-1-phenyl-1H-pyrazole with heterocyclic amines followed by air oxidation in the presence of cupric acetate.     

Synthesis of 1-phenyi-1H-tetrazolo[4,5-d]tetrazole and 5-aryl-1-(4-bromophenyl)-1,2,4-triazolo[4,3-d]tetrazoles

l-Phenyl-lH-tetrazol-5-yIhydrazine (2) was reacted with nitrous acid to yield 1-phenyl-lH-tetrazolo[4,5-d]tetrazole (3). l-Arylidene-2-(l-phenyl-lH-tetrazol-5-yl)hydrazines (4) were generally reactive towards electrophilic reagents. When treated with bromine in acetic acid, 4 yielded mixtures of 1-arylidene-2-[1-(4-bromophenyl)-lH-tetrazol-5-yl]hydrazines (5a-d) and 2-[1-(4-bromophenyl)-lH-tetrazol-5-yl]hydrazidic bromides (6a-d). Solvolysis of 6a-d in aqueous acetone yielded 5-aryl-1-(4-bromophenyl)-1,2,4-triazolo[4,3-d]tetrazoles (7a-d). The structures of the synthesized compounds were confirmed on the basis of elemental analysis, IR and ¹H NMR data.     

Substitution reactions of phenanthro[9,10-d]triazole with benzyl chlorides

The reaction of the potassium salt of phenanthro[9,10-d]triazole and benzyl chloride gave 2-(benzyl)-2H-phenanthro[9,10-d]triazole ( 2a ) in 15% yield. The other regio-isomer, 1-(benzyl)-1H-phenanthro[9,10-d]-triazole ( 1a ), was obtained as a by-product in 3.9% yield. Similar reactions with benzyl chlorides having a methyl, a chloro or a nitro group on the aromatic ring gave the corresponding two products, 1b-j and 2b-j . In all cases, 2b-j were major products in yields of 14–62%, 1b-j were minor ones in yields of 1.4–7.6%. The structures of the isomers were confirmed by X-ray crystal analyses.