Synthesis of Spiro[benzo[h]chromene-4,3′-indoles] and Spiro[benzo[f]chromene-1,3′-indoles]

Russian Journal of Organic Chemistry - New spiro heterocycles, spiro[benzo[h]chromene-4,3′-indoles] and spiro[benzo[f]chromene-1,3′-indoles], have been synthesized in 50–60% yield...     

STUDIES ON PHOSPHONIUM YLIDS‐VIII. WITTIG REACTION WITH N,N′-3,5-CYCLO-HEXADIENE-1,2-DIYLIDENEBIS[BENZAMIDE]

Abstract

The reaction of methylenetriphenylphosphoranes (1) with N,N′-3,5-cyclohexadiene-1,2-diylidenebis [benzamide] (2) afforded new ylid-phosphoranes of type 3. The mechanism that accounts for formation of adducts 3 is discussed. Structural reasoning for compounds 3 was based on compatible analytical, chemical and spectroscopic results.     

Catalyst-free glycerol-mediated green synthesis of 5′-thioxospiro[indoline-3,3′-[1,2,4]triazolidin]-2-ones/spiro[indoline-3,3′-[1,2,4]triazolidine]-2,5′-diones

The development of new catalyst-free green and efficient protocol to access 5′-thioxospiro[indoline-3,3′-[1,2,4]triazolidin]-2-ones/spiro[indoline-3,3′-[1,2,4]triazolidine]-2,5′-diones, potential privileged scaffolds for drug discovery, is disclosed. Key feature of this methodology is the dual use of glycerol—a recyclable, bioorganic compound, as a solvent cum promoter. Other highlights include use of inexpensive reagents, mild reaction conditions, operational simplicity, short reaction time, no need for chromatographic purification, and high yields.     

Synthesis of 4′-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-ones

N-Boc-protected 8-azaspiro[bicyclo[3.2.1]octane-3,2′-oxirane] reacted with primary aliphatic amines through opening of the epoxide ring with formation of the corresponding amino alcohols which were converted into N-chloroacetyl derivatives. The latter underwent cyclization to N-Boc-protected 4′-alkyl-8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-ones by the action of sodium hydride in DMF, and subsequent treatment with hydrogen chloride in ethyl acetate afforded 8-azaspiro[bicyclo[3.2.1]octane-3,2′-morpholin]-5′-one hydrochlorides.     

Synthesis of Bisindolylindeno[1,2-b]quinoxaline and Bisindolylindeno[3,4-b]pyrazine with Poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide)

Poly(N,N′-dibromo-N-ethylnaphthyl-2,7-disulfonamide) (PBNS) as novel reagent was synthesized. Bisindolylindeno[1,2-b]quinoxaline and bisindolylindeno[3,4-b]pyrazine derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of indole, indane-1,2,3-trione, and diamine aromatic compounds by PBNS under solvent-free conditions at 80 °C in good to excellent yields, short reaction times, and a simple procedure for new derivatives.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications^® for the following free supplemental resource(s): Full experimental and spectral details.]     

Condensed pyridopyrimidines. 1. Synthesis of new derivatives of pyrano[3′,4′∶5,6]pyrido[2,3-d]pyrimidines

New derivatives of pyrano[3,45,6]pyrido[2,3-d]pyrimidines were synthesized from ethyl 2-amino-7,7-dimethyl-7,8-dihydro-5H-pyrano[4,3-b]pyridine-3-carboxylate.A. L. Mndzhoyan Institute of Fine Organic Chemistry, National Academy of Sciences of the Republic of Armenia, Erevan. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1239–1241, September, 1999.     

Sequential Multistep Excited-State Structural Transformations in N,N′-Diphenyl-dihydrodibenzo[a,c]phenazine Fluorophores

We demonstrate that a single polycyclic π-scaffold can undergo sequential multistep excited-state structural evolution along the bent, planar, and twisted conformers, which coexist to produce intrinsic multiple fluorescence emissions in room-temperature solution. By installing a methyl or trifluoromethyl group on the ortho-site of N,N′-diphenyl-dihydrodibenzo[a,c]phenazine ( DPAC ), the enhanced steric effects change the fluorescence emission of DPAC from a dominant red band to well-resolved triple bands. The ultra-broadband triple emissions of ortho-substituted DPAC s range from ≈350 to ≈850 nm, which is unprecedented for small fluorophores with molecular weight of <500. Ultrafast spectroscopy and theoretical calculations clearly reveal that the above dramatic changes originate from the influence of steric hindrance on the shape of excited state potential energy surface (S₁ PES). Compared to the steep S₁ PES of parental DPAC , the introduction of ortho-substituent is shown to make the path of structural evolution in S₁ wider and flatter, so the ortho-substituted derivatives exhibit slower structural transformations from bent to planar and then to twisted forms, yielding intrinsic triple emission. The results provide the proof of concept that the bent, planar, and twisted emissive states can coexist in the same S₁ PES, which greatly expand the fundamental understanding of the excited-state structural relaxation.     

Dipyrrolo[1,2-a; 2′,1′-c]pyrazines. 4. Aminomethylation of alkyl substituted dipyrrolo[1,2-a; 2′,1′-c]pyrazines and 5,6-dihydrodipyrrolo[1,2-a; 2′,1′-c]pyrazines

We have studied the aminomethylation reaction of alkyl substituted dipyrrolo[1,2-a; 2,1-c]pyrazines and their 5,6-dihydro analogs using different aminomethylating agents. Use of alkoxydialkylaminomethanes (aminoacetals) as Mannich reagents leads to the highest yields of the aminomethylated dipyrrolopyrazines. The compounds prepared have been studied by mass spectrometry.For Communication 3, see [1].M. V. Lomonosov State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–957, July, 1998.     

Dipyrrolo[1,2-a; 2′,1′-c]pyrazines. 5. Azo coupling of dipyrrolo[1,2-a;2′,1′-c]pyrazines and 5,6-dihydrodipyrrolo[1,2-a; 2′,1′-c]pyrazines

We have synthesized a series of previously unreported azo dyes via the azo coupling of alkyl substituted dipyrrolopyrazines with aryldiazonium chloride. For this type of substrate where one or both -positions of the pyrrole rings of the molecules are not occupied by substituents, electrophilic attack was found to occur initially at carbon atom C₍₃₎.For communication 4 see [1]M. V. Lomonosov State University, Moscow 119899, Russia Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 236–240, February, 1999.     

Stereoselective [4+2] cycloadditions of tetrazines to 3-oxo- and 3-arylimino-4′-methylenedihydro-3′H-spiro[bicyclo[2.2.1]heptane-2,2′-furans]

Stereoselective inverse-demand [4+2] cycloadditions of 3,6-bis(pyridin-2-yl)-1,2,4,5-tetrazine and dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate to 4′-methylenedihydro-3′H-spiro[bicyclo[2.2.1]heptane-2,2′-furans] and 4′-methylene-1′-(4-nitrophenyl)spiro[bicyclo[2.2.1]heptane-3,2′-pyrrolidine] were studied. Cycloadditions took place stereoselectively at the exocyclic CC double bonds to give novel 11:14-isopropylidene-14-methyl-2,3-diaza-8-oxadispiro[5.1.5.2]pentadecane and 11:14-isopropylidene-11-methyl-2,3,8-triazadispiro[5.1.5.2]pentadecane derivatives in 50–98% de. The structures of the novel dispiro compounds were determined by NMR techniques, NOESY spectroscopy and X-ray diffraction.     

Synthesis of 4′H-spiro[adamantane-2,3′-isoquinoline] derivatives

Russian Journal of Organic Chemistry -     

4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane N,N′-dioxide tetrahydrate: Synthesis and crystal structure

N,N′-Substituted 2.2.2-cryptand, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane N,N′-dioxide, is synthesized by an unusual method. The X-ray diffraction crystal structure of its tetrahydrate (C₁₈H₃₆N₂O₈) · 4H₂O is studied (space group P $\bar 1$ , a = 8.040 Å, b = 11.883 Å, c = 14.451 Å, α = 65.78°, β = 81.10°, γ = 89.12°, Z = 2) by a direct method and refined by the least-squares method in the anisotropic approximation (R = 0.069 for 3244 independent reflections, CAD4 automated diffractometer, λMoK _α radiation). The macrocyclic molecule has exo-exo conformation with the two O atoms at the N atoms directed outside its cavity. A crystal of compound I contains hydrogen bonds formed by all H atoms of all water molecules; these H-bonds link the water molecule into zigzag-like complicated infinite chains.     

Formation of 3,4-diazabicyclo[4,3,0]non-2-ene and N,N′-azo-3-azabicyclo[3,3,0]octane by oxidation of an alicyclic hydrazine. influence ofpH on the diazene rearrangement

Summary 3,4-Diazabicyclo[4,3,0]non-2-ene and N,N-azo-3-azabicyclo[3,3,0]octane are the main products of the oxidation of N-amino-3-azabicyclo[3,3,0]octane by chloramine. The reaction leads to the transient formation of a saturated bicyclic aminonitrene (diazene). AtpH > 13, the diazene undergoes an intramolecular rearrangement to afford a hydrazone. AtpH < 9, a white solid is formed resulting from the dimerization of the molecular and protonated forms of the aminonitrene. At intermediatepH-values, a mixture of both species is obtained. They have been isolated and characterized by UV, GC/MS, IR, and¹H/¹³CNMR. A reaction mechanism is proposed.

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Bildung von 3,4-Diazabicyclo[4,3,0]non-2-en und N,N-Azo-3-azabicyclo[3,3,0]oktan durch Oxidation eines alizyklischen Hydrazins. Einfluß despH-Wertes auf die Umlagerung von Diazenen

Zusammenfassung 3,4-Diazabicyclo[4,3,0]-non-2-en und N,N-Azo-3-azabicyclo[3,3,0]oktan sind die Hauptreaktionsprodukte der Oxidation von N-Amino-3-azabicyclo[3,3,0]oktan durch Chloramin. Die Interaktion führt übergangsweise zur Bildung eines gesättigten bizyklischen Aminonitrens (Diazens). Oberhalb despH-Wertes 13 lagert sich das Diazen intramolekular um und bildet ein Hydrazon. Unterhalb despH-Wertes 9 fällt ein weißer Niederschlag aus (Tetrazen), der von einer Dimerisierung zwischen for molekularen und protonierten Form von Aminonitren herrühren dürfte. Für die dazwischenliegenden Werte (9 <pH < 13) erhält man eine Mischung aus beiden Verbindungen. Sie wurden isoliert und mit Hilfe von UV, GC/MS, IR, und¹H/¹³C-NMR untersucht. Ein Reaktionsmechanismus wird vorgeschlagen.

     

Condensed isoquinolines 32. Synthesis of 4H-thieno-[3′,2′:5,6]-and-[2′,3′: 5,6]pyrimido-[1,2-b]isoquinolines and 6,12-dihydro-5H-isoquino-[2,3-a]quinazoline-5,12-dione derivatives

Treatment of 2-(4-oxo-3,4-dihydrothieno[2,3-d]-and-[3,2-d]pyrimidin-2-ylmethyl)benzoic acids and 2-(4-oxo-3,4-dihydro-2-quinazolinylmethyl)benzoic acid with acetic anhydride gave thieno[3′,2′:5,6]-and-[2′,3′:5,6]pyrimido[1,2-b]isoquinoline-4,11-diones and isoquino[2,3-a]quinazoline-5,12-dione respectively. NMR spectroscopy showed that an intramolecular acylation of the above acids occurs at the atom N-1 of the pyrimidinone part of the bicycle. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1053–1061, July, 2008.     

Reaction of tert-Butylcyanoketene with 2′-Cyclohexylspiro [Fluorene-9,3′-Oxaziridine]

Although the reactions of ketenes and three-membered heterocycles containing one hetero atom are well known,^1,2 only one investigation of similar recations with three-membered rings containing two hetero atoms has been reported.³ The reaction of 2-ethyl-3-phenyloxaziridine with diphenylketene was found to afford among other minor products an oxazolidinone derivative (1) and benzaldehyde in yields of 38% and 50% respectively.     

Synthesis and fungicidal activity of N,N′-dithol-4-yl-1,3,5-thiadiazinane and N,N′-[methylene-bis-(thiomethylene)]-bis-[4(5)-methyl-1,3-thiazole-2-amines]

Thiomethylation of para-toluidine and 4(5)-methyl-2-aminothiazoles was used to synthesize N,N′-dithol-4-yl-1,3,5-thiadiazinane and N,N′-[methylene-bis-(thiomethylene)]-bis-[4(5)-methyl-1,3-thiazole-2-amines]. A fungicidal and fungistatic effect toward some microscopic fungi, plant-disease-producing factor, was revealed for these compounds.     

Synthesis of new heterocyclic systems—substituted spiro[chromene-4,3′-indoles] and spiro[indole-3,4′-quinolines]

Methods have been developed for the synthesis of new heterocyclic systems, spiro[chromene-4,3′- indoles] and spiro[indole-3,4′-quinolines] by the base-catalyzed domino reaction of isatins with 5,5-dimethylcyclohexane- 1,3-dione (or 5,5-dimethyl-3-anilinocyclohex-2-en-1-one) and ethyl cyanoacetate.     

Dipyrrolo[1,2-a; 2′,1′-c]pyrazines. 1. Quantum-chemical study of dipyrrolo[1,2-a; 2′,1′-c]pyrazines in electrophilic substitution reactions

The semiempirical quantum-chemical method PM3 has been used in a study of the electronic and spatial structure of dipyrrolo[l , 2-a; 2,1-cjpyrazines and 5,6-dihydrodipyrrolo[1,2-a; 2,1-cjpyrazines, and also their reactivities in electrophilic substitution reactions (protonation, acylation).M. V. Lomonosov Moscow State University, Moscow 119899 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1559–1565, November, 1995. Original article submitted September 13, 1995     

Polyanthranilides. III. Synthesis and Characterization of Polyamides from 6,6′-Bis[3,1-benzoxazin-2,4-dione]

Ring-scission polymerization of 6,6′-bis[3, 1-benzoxazin-2,4-dione] was studied in presence of such catalysts as aqueous HC1, benzidine-3,3′-dicarboxamide, N-methyl aniline, o-chloroaniline, benzidine-3,3′-dicarboxylic acid, and acid amides under various experimental conditions. It was found that 6,6′-bis[3,1-benzoxazin-2,4-dione] undergoes ring-scission polymerization, affording polyanthranilides in the presence of the first five catalysts under appropriate experimental conditions. The samples are insoluble in all organic solvents including formic acid. They are soluble in sulfuric acid with degradation. They are characterized by IR spectral and thermogravimetric analysis.