Synthesis and properties of phenothiazine derivatives. I. Synthesis and properties of bisoxytriazenes containing the phenothiazine fragment

3, 7-Bis(1-phenyl-3-hydroxytriazenyl)phenothiazine has been synthesized from phenothiazine. This compound decomposes to phenyl radicals, nitrogen and 3, 7-bisnitrosophenothiazine under the influence of nitroso compounds and oxidizing agents (PbO₂, Ag₂O). The reaction of bishydroxytriazenylphenothiazene with 2, 4, 6-tribromonitrosobenzene has been studied by EPR spectroscopy.N. P. Ogarev Mordov State University, Saransk 430000. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1284–1287, September, 1996. Original article submitted March 21, 1996.     

1,2,5-Selenadiazoles. Synthesis and properties

4-Amino-1, 2, 5-selenadiazole-3-carboxylic acid and 4-amino-1, 2, 5-selenadiazole-3-carboxamides have been prepared by ring-cleavage of [1, 2, 5]selenadiazolo[3, 4-d]pyrimidin-7(6H)-one by basic reagents. The primary amide (III), as well as an N-alkyl amide, may be produced by the action of a primary amine. Hydrazine reductively cleaves the selenadiazole ring. The preparation of similar 4-ureido derivatives by ring-cleavage of [1,2,5]selenadiazolo[3, 4-d]pyrimidine-5, 7(4 H, 6H)-dione has been demonstrated with two examples. N-Butyl-4-ureido-1, 2, 5-selenadiazole-3-carboxamide is easily hydrolyzed in aqueous base to the corresponding acid, and it has been shown that this reaction proceeds by way of [1, 2, 5]selenadiazolo[3,4-d]pyrimidine-5, 7 (4H, 6H)-dione. The 4-amino-1, 2, 5-selenadiazole-3-carboxylic acid derivatives have marked cytotoxic, antibacterial, and antifungal activity.     

Pteridines. Part XCVII. Synthesis and properties of 6-thioxanthopterin and 7-thioisoxanthopterin

6-Thioxanthopterin ( 13 ) was synthesized in four steps starting from 2-amino-4-(penthyloxy)pteridine ( 3 ) via the 8-oxide 4 , its subsequent interconversion to the 6-chloro ( 7 ) and 6-thio derivative ( 12 ) and final hydrolysis of the pentyloxy group. 7-Thioisoxanthopterin ( 15 ) was derived analogously from 2-amino-4-(pentyloxy)pteridine-7(8H)-thione ( 14 ) by alkaline hydrolysis. The various 6- and 7-thiopteridines were methylated to give the corresponding 6- ( 10, 11 ) and 7-(methylthio) derivatives ( 16, 17 ). The newly synthesized compounds have been characterized by elemental analyses, their UV spectra, and the determination of the acidic and basic pK_a values. The spectral relationships are discussed in detail.     

Polynucleotide analogues. VI. Synthesis and characterization of alternating copolymers of maleic anhydride and dihydropyran containing guanine derivatives

2-Amino-6-chloropurine was reacted with 2-(tosyloxymethyl)-2,3-dihydro-2H-pyran to give 2-(2-amino-6-chloropurin-9-ylmethyl)-2,3-dihydro-2H-pyran ( 3 ) and its N⁷-isomer ( 4 ), which were treated with 5% aqueous trimethylamine to result in 2-(guanin-9-ylmethyl)-2,3-dihydro-2H-pyran ( 5 ) and its N⁷-isomer ( 6 ), respectively. 2-(N²-Acetylguanin-9-yl-methyl)-3,4-dihydro-2H-pyran ( 7 ) and 2-(N²-acetylguanin-7-ylmethyl)-3,4-dihydro-2H-pyran ( 8 ), obtained by acetylation of compounds 5 and 6 , were copolymerized with maleic anhydride to give the alternating copolymers 9 and 10 , and they were hydrolyzed to result in poly[ {2-(guanin-9-ylmethyl)tetrahydropyran-5,6-diyl} {1,2-dicarboxyethylene}] ( 11 ) and poly[ {2-(guanin-7-ylmethyl)tetrahydropyran-5,6-diyl} {1,2-dicarboxyethylene}] ( 12 ), re-spectively. Polymer 11 showed hypochromicity whereas 12 exhibited hyperchromicity in aqueous solutions. Polymers 11 and 12 in aqueous solutions showed very strong excimer fluorescence with the maximum intensities at 432 and 446 nm, respectively, at room tem-perature. The two polymers showed polyelectrolyte effects, e.g., very high GPC molecular weights as well as reduced viscosities at low concentrations in water. Normal behavior was retained by addition of inorganic salts. Sodium salts of polymers 11 and 12 migrated to the anode by electrophoresis and both showed two bands. © 1995 John Wiley & Sons, Inc.     

Diisophorone and related compounds. Part 19 Synthesis and reactions of 6,8-dibromodiisophorones

Novel 6,8-dibromo-derivatives of diisophor-2(7)-en-1-ol-3-one and the corresponding 1-carboxylic acid methyl ester are readily accessible by the action of 2 mol of N-bromosuccinimide on the respective parent compounds. Treatment with alkali converts the 6,8-dibromo-ketol, by a simultaneous 8-substitution and ring A-aromatisation, into 6-methyl-5-nordiisophora-2(7),3,5-triene-1,3,8-triol; acetolysis and methanolysis produce the corresponding 8-acetoxy- and 8-methoxy-compounds. The 6,8-dibromo-1-carboxylic acid reacts analogously, with the added option of 1,3-lactone formation. The assigned¹³C-nmr spectra and fragmentation patterns of the new compounds are in accord with their proposed formulation.

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Diisophoron und verwandte Verbindungen, 19. Mitt.: Synthese und Reaktionen von 6,8-Dibromdiisophoronen

Zusammenfassung Neuartige 6,8-Dibrom-Abkömmlinge des Diisophor-2(7)-en-1-ol-3-ons und der entsprechenden 1-Carbonsäure (als Methylester) sind durch Einwirkung von 2 mol N-Bromsuccinimid auf die betreffende Grundverbindung leicht zugänglich. Bei der Umsetzung des 6,8-Dibromketols mit Alkalien entsteht 6-Methyl-5-nordiisophora-2(7),3,5-trien-1,3,8-triol, unter gleichzeitiger 8-Substituierung und Ring-A-Aromatisierung. Acetolyse und Methanolyse ergeben die entsprechenden 8-Acetoxy- und 8-Methoxy-Verbindungen. Die 6,8-Dibrom-1-carbonsäure reagiert analog, mit weiterer Möglichkeit zur 1,3-Lacton-Bildung. Die¹³C-Kernresonanz-und Massenspektren der neuen Verbindungen stehen mit den Strukturzuordnungen im Einklang.

     

Synthesis and properties of furan derivatives. 5. Synthesis of 2-substituted benzoxazoles containing furan fragments

The condensation of imidates and imidate hydrochlorides of furan acids with o-aminophenols gives furyl derivatives of 2-substituted benzoxazoles. Such compounds are also formed in the reaction of furan acids with o-aminophenol in the presence of boric acid.Communication 4, see [1].I. M. Gubkin State Petroleum and Gas Academy, 117917 Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 896–901, July, 1996. Original article submitted April 16, 1996.     

252. Synthesis and reactions of droso- and isodrosopterin. Pteridines. LIV

The synthesis of the Drosophila pigments droso- and isodrosopterin ( 7 ) from 7.8-dihydropterin ( 3 ) and 2-hydroxy-3-oxobutyric acid ( 4 ) is described. A reaction mechanism is discussed and proven by isotope experiments. Droso- and isodrosopterin form in weak acidic medium in the presence of NH ions two red reaction products each one of which seems to be identical with neodrosopterin.     

1,6- and 1,7-naphthyridines. II. Synthesis from acyclic precursors

A number of 8-hydroxy-6-methyl-1,6-naphthyridin-5(6H)-one-7-carboxylic acid alkyl esters 3 and the isomeric 5-hydroxy-7-methyl-1,7-naphthyridin-8(7H)-one-6-carboxylic acid alkyl esters 4 were synthesized from acyclic precursors obtained starting from quinolinic anhydride 5. Thus, methanolysis of 5 afforded the hemiester 6 which treated with oxalyl chloride and sarcosine ethyl ester gave 3-(N-ethoxycarbonylmethyl-N-methylcarbamoyl)pyridine-2-carboxylic acid methyl ester 8. Compound 8 was cyclized to naphthyridines 3a-e with sodium alkoxides. The isomeric naphthyridines 4a-c were obtained by cyclization of the open intermediary 2-(N-ethoxycarbonylmethyl-N-methylcarbamoyl)pyridine-3-carboxylic acid methyl ester 9 obtained by a route that involves treatment of 5 with sarcosine ethyl ester and esterification with diazomethane. Spectroscopic properties (¹H nmr, uv, ir) of compounds 3 and 4 are discussed and confirmed the proposed structures.     

Synthesis of 5-aryl-2-oxazolepropionic acids and analogs. Antiinflammatory agents

Condensation of 2-bromoacetophenones with sodium succinimide gave N-phenacylsuccinimides ( 1 ) which were opened with sodium hydroxide to N-phenacylsuccinamic acids ( 2 ). The latter were cyclized to 5-aryl-2-oxazolepropionic acids ( 3 ) in sulfuric acid. Similar cyclization of N-phenacylphthalamic acid ( 5 ) and succinic acid 2-benzoylhydrazide ( 7 ) gave o-(5-phenyl-2-oxazolyl)benzoic acid ( 6 ) and 5-phenyl-1,3,4-oxadiazole-2-propionic acid ( 8 ). The succinamic acids 2 and the phthalamic acid 5 were observed to recyclize to the corresponding imides ( 1 and 4 ) on heating, and the succinic acid hydrazide 7 was similarly cyclized to N-benzamidosuccinimide ( 9 ) with acetic anhydride. Antiinflammatory screening data are reported for 3 , 6 and 8 .     

Purines. XIV. Synthesis and properties of 8-nitroxanthine and its N-methyl derivatives

Xanthine ( 1 ) and its N-methyl derivatives 2–16 have been nitrated to the corresponding 8-nitro derivatives 17–32 under different reaction conditions. Nitration in glacial acetic acid with nitric acid works well with the N-7 unsubstituted and some of the 9-methylxanthines, respectively, whereas the 7-methylxanthine derivatives react best with nitronium tetrafluoroborate in sulfolane or glacial acetic acid. The 8-nitro group can be displaced nucleophilically to form 8-chloro-, 33, 34 , 8-ethoxy-, 35,36 , and uric acid derivatives 37–40 , respectively. The newly synthesized 8-nitroxanthines have been characterized by elemental analyses, pK-determinations and uv and ¹H-nmr spectra.     

Streptonigrin and related compounds III. Synthesis and microbiological activity of destrioxyphenylstreptonigrin and analogues

Synthesis of three tricyclic analogues of streptonigrin, based on the 2-(2′-pyridyl)quinoline-5,8-dione system and with the characteristic substitution pattern of rings A and C of streptonigrin is described. The C-ring precursor, in the form of a substituted 2-acetylpyridine was condensed with either 3-hydroxy-5-methoxy-2-nitrobenzaldehyde or 3-hydroxy-4-methoxy-2-nitrobenzaldehyde, followed by reductive cyclization and oxidation to the corresponding quinones 12 and 29 . The 7-amino substitution was introduced in 12 via bromination and azidation. The 6-amino substitution was introduced through direct reaction of 29 with sodium azide. Destrioxyphenylstreptonigrin 2 was twice as active and the 6-amino-7-inethoxy analogue 4 was as active as streptonigrin in a microbiological assay. A 4′-bromo analogue of 2 was 60% as active as streptonigrin.     

2-Imidazolines. IV . 1-Aryl-2-alkylthio-4,5- diamino-4,5-dihydroimidazoles. Synthesis and properties

1,2-Diimmonium salts ( 1 ) react with S-substituted isothioureas ( 3 ) yielding 2-alkylthio-4,5-diamino-4,5-dihydroimidazoles ( 4 ), which under mild pyrolytic conditions afforded 2-alkylthio-5-aminoimidazoles ( 7 ). Imidazolines ( 4 ) and imidazoles ( 7 ) were easily desulfurated with Raney nickel affording 4,5-diamino-4,5-dihydroimidazole ( 9 ) and 5-aminoimidazole ( 10 ), respectively.     

Synthesis and properties of azoles and their derivatives. 35. Synthesis of certain azoles containing sterically hindered phenol residues

The condensation of hydrochlorides of ethyl iminoesters of 4-hydroxy-3,5-di-tert-butylbenzoic and -(4-hydroxy-3,5-di-tert-butylphenyl) propionic acids with monoethanolamine, o-aminophenol, and o-phenylenediamine was studied. As a result, ²-oxazolines, benzoxazoles, and benzimidazoles containing sterically hindered phenol residues in the 2-position were synthesized.For Communication 34, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 889–892, July, 1984.     

Potential cerebral perfusion agents. Synthesis and evaluation of new radioiodinated barbituric acid analogs

Two new ¹²⁵I-labeled barbituric acid analogs, 5-ethyl-5-(E-1-iodo-1-penten-5-yl)2-thiobarbituric acid ( 4 ) and 5-ethyl-5-( m -iodophenyl)barbituric acid ( 7 ), have been prepared and evaluated in rats as potential cerebral perfusion agents. Annulation of 2-ethyl-2-(E-1-iodo-1-penten-5-yl)malonate ( 3 ) with thiourea in the presence of sodium ethoxide gave the 5-ethyl-5-(E-1-iodo-1-penten-5-y1)-thiobarbituric acid ( 4 ). Diethyl 2-ethyl-2-phenyl-malonate was treated with thallium(III) trifluoroacetate followed by addition of aqueous potassium iodide to provide diethyl 2-ethyl-2-(m-iodophenyl)malonate ( 10 ). The malonic ester derivative 10 was condensed with urea in the presence of sodium hydride to give the desired 5-ethyl-5-(m-iodophenyl)barbituric acid ( 7 ), and a decarbethoxylation product, 2-(m-iodophenyl)butyric acid ( 11 ). Iodine-125-labeled 4 and 7 were synthesized in the same manner and the tissue distribution of these new agents evaluated in rats. Both [¹²⁵I] 4 and [¹²⁵I] 7 showed high brain uptake. Significant in vivo deiodination was detected with [¹²⁵I] 4 whereas [¹²⁵I] 7 was found to be stable to deiodination.     

Heteroadamantanes and their derivatives. 4. Synthesis of 1,3,5-triazaadamantane

Reduction of 7-nitro-1,3,5-triazaadamantane with hydrazine hydrate in the presence of Raney nickel gave 7-hydroxyamino- and 7-amino-1,3,5-triazaadamantane, from which 7-chloro-, 7-bromo-, and 7-thiocyanato-1,3,5-triazaadamantanes were synthesized by substitutive deamination. Desulfurization of 7-thiocyanato-1,3,5-triazaadamantane in the presence of Raney nickel gave 1,3,5-triazaadamantane.For Communication 3, see [1].Translated from Khitniya Geterotsiklicheskikh Soedinenii, No. 6, pp. 837–840, June, 1985.     

Synthesis and transformations of polyhedral compounds. 16. Synthesis and some reactions of 7-aroyl- and 7-heteroyl-1,3,5-triazaadamantanes

7-Aroyl- and 7-heteroyl-1,3,5-triazaadamantanes were obtained by condensation of aromatic and heterocyclic compounds containing an acetyl group with hexamethylenetetramine in the presence of acetic acid. Reactions with 7-benzoyl- and 7-(4-nitrobenzoyl)-1,3,5-triazaadamantanes at both the carbonyl group and in the triazaadamantane ring were carried out. Ring-deuterated 7-nitro- and 7-(4-nitrobenzoyl)-1,3,5-triazaadamantanes were synthesized in order to ascertain the pathway of mass-spectrometric fragmentation, as well as a possible mechanism for the construction of the triazaadamantane ring.For Communication 15 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1565–1571, November, 1992.     

Reaction of 1,2-diamino-4-nitrobenzene with 1,5-diketones. Synthesis and oxidative reactions of nitrobenzimidazoles

Reaction of 1,5-diketones with 1,2-diamino-4-nitrobenzene gave a mixture of the 6- and 7-nitro derivatives of 4a,9-diaza-1,2,4a,9a-tetrahydrofluorene. Oxidation of the 6-nitro derivatives with MnO₂ gives para-quinone imines with elimination of the nitro groups. Oxidation of the 7-nitro derivative and oxidative conjugation of 5-nitro-2,2-pentamethylene-1,2-dihydrobenzimidazole with primary amines in the presence of MnO₂ gives nitro ortho-quinone imines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 927–930, July, 1990.     

Synthesis and reactions of halo-, nitro-, and arylazo-substituted 3-acetyltropolones. Formation of heterocycle-fused troponoid compounds

3-Acetyltropolone ( 1 ) reacted with bromine, iodine, and nitric acid to afford respectively 3-acetyl-5,7-di-bromotropolone ( 2 ), 3-acetyl-7-iodotropolone ( 3 ), and 3-acetyl-5-nitro- ( 4 ) and 3-acetyl-5,7-dinitrotropolone ( 5 ). Azo-coupling reactions of 1 gave 3-acetyl-5-arylazotropolones 7a-f. The Schmidt reactions of 2 and 3 gave respectively 5,7-dibromo- ( 9 ) and 7-iodo-2-methyl-8H-cyclohept[d]oxazol-8-one ( 10 ), while 4 gave 3-acetamido-5-nitrotropolone ( 11 ). Compounds 2 and 4 reacted with hydroxylamine to give 3-methyl-8H-cyclohept[d]isoxazol-8-ones 12 and 13. The reactions of 2 , 3 , and 4 with hydrazine gave 3-methyl-1,8-dihydrocycloheptapyrazol-8-ones 15 , 16 , and 17.     

Synthesis and interconversion of isomeric pyrrolotriazolopyrimidines

4‐Hydrazino‐7H‐pyrrolo[2,3‐d]pyrimidines 4 were cyclocondensed with formic acid or triethyl orthoformate to give 7H‐pyrrolo[3,2‐e][1,2,4]triazolo[1,5‐c]pyrimidines 6 and 7H‐pyrrolo[3,2‐e][1,2,4]triazolo[4,3‐c]pyrimidines 7 , respectively. The [4,3‐c] isomers 7 were rearranged into thermodynamically more stable [1,5‐c] isomers 6 . The identical compounds 6 were prepared using another route by reacting 3‐amino‐4‐imino‐7H‐pyrrolo[2,3‐d]pyrimidines 3 with formic acid or triethyl orthoformate. The reaction of 2‐amino‐3‐cyanopyrroles 1 with triethyl orthoformate gave N‐ethoxymethylene‐2‐amino‐3‐cyanopyrroles 2 . Further reaction with an equivalent of hydrazine hydrate provided 3‐amino‐4‐imino‐7H‐pyrrolo[2,3‐d]pyrimidines 3 , whereas treatment with excess of hydrazine hydrate, 3 rearranged to 4‐hydrazino‐7H‐pyrrolo[2,3‐d]pyrimidines 4 . Compounds 4 were also obtained by the treatment of N‐ethoxymethylene‐2‐amino‐3‐cyanopyrroles 2 in excess of hydrazine hydrate. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:265–273, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20295     

Lutetium complexes with tetraphenylethylene dianion. Synthesis and structure

The reactions of dipotassium and disodium salts of the tetraphenylethylene dianion with LuCl₃(THF)₃ or CpLuCl₂(THF)₃ yielded the homoleptic ate-complexes [Na(THF)₅][Lu(Ph₂CCPh₂)₂] (1) and [K(THF)₅][Lu(Ph₂CCPh₂)₂] (2) or the heteroleptic complex CpLu(Ph₂CCPh₂)(THF)₂ (4), respectively. Recrystallization of complex 1 from a diglyme—THF mixture afforded [Na(diglyme)₂][Lu(Ph₂CCPh₂)₂](THF)_0,5 (3). Recrystallization of complex 4 from 1,2-dimethoxyethane gave [CpLu(Ph₂CCPh₂)(DME)](DME) (5). The structures of complexes 3 and 5 were established by X-ray diffraction analysis. In both complexes, the unusual η⁶-coordination of the (Ph₂CCPh₂)²⁻ dianion to lutetium is observed. The Lu-C distances vary from 2.441(2) to 2.643(2) Å (3) and from 2.470(3) to 2.763(3) Å (5). In complexes 3 and 5, a redistribution of the C-C bond lengths was observed in the Ph groups coordinated to lutetium. Studies by ¹H, ¹³C, and 2D NMR spectroscopy demonstrated that the η⁶-coordination of the tetraphenylethylene dianion in homoleptic ate-complexes 1 and 2 is retained in a THF solution, whereas the coordination of this dianion in heteroleptic complex 4 changes from η⁶ to η⁴.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2060–2068, October, 2004.