Amination of 4-Azafluorene under Chichibabin Reaction Conditions. Some Chemical Transformations of 1-Amino-4-azafluorene

4-Azafluorene is aminated by sodium amide in dimethylaniline at C₍₁₎. The oxidation of 1-amino-4-azafluorene was studied along with the condensation of this compound with acetic anhydride and its diazotization.     

Acylation of 3-methyl-2-azafluorene

Acylation of 3-methyl-2-azafluorene under various conditions yielded the enol forms of its (C₍₉₎ acyl derivatives, whereas the ketol form was also isolated in the case of the p-nitrobenzoyl derivative. The character of the compounds formed in the reaction of 3-methyl-2-azafluorene with benzoyl chloride and acetic anhydride is discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–967, July, 1976.     

Chemistry of 2-hetarylbenzimidazoles. 10. Synthesis and properties of 2-(3′-furyl)-1-methyl-1H-benzimidazole

A study was carried out on the electrophilic substitution reactions such as chloromethylation, bromination, sulfonation, nitration, and acylation of 2-(3′-furyl)-1-methyl-1H-benzimidazole in acid media. All these reactions proceed at C₍₂₎ and C₍₅₎ of the furan ring. Quantum-chemical calculations of the three-dimensional structure of such heterocyclic systems are given. Communication 9, see ref. [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1815–1820, December, 2005.     

Synthesis and transformations of 1-methyl-4-azafluorene

By means of catalytic dehydrocyclization of dimethyl-substituted 2-phenylpyridines in a pyridine ring to 1(2,3)methyl-4-azafluorenes with subsequent oxidation, synthesis of alkaloid onychine — 1-methyl-4-azafluorene — several of its isomers were achieved. Using 1-methyl-4-azafluorene, we obtained a C₉ furfurylidene product, substituted tetrahydroindine[1,2-b]pyridine and NH-indine[1,2-b]-pyridine. We obtained 7-nitro-1-methyl-4azafluorene by nitration of onychine and oxidation of nitro-substituted azafluorene; this indicates an identical orientation of 4-azafluoren(one) and fluoren(one) during nitration.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 513–517, April, 1982.     

Cyclodimerization of 1-(Dimethoxyniethyl)-5,6-dimethylidene-7-oxa-bicyclo[2.2.1]hept-2-ene Induced by Nonacarbonyldiiron. Crystal Structure of (1RS, 2SR, 3RS, 4RS, 4aRS, 9aSR)- Tricarbonyl[C, 2,3, C-η-(1,4-epoxy-1,5-bis(dimethoxymethyl)-2,3-dimethylidene-1,2,3,4,4a,9,9a,10-octahydroanthracene)]iron

The transition-metal-carbonyl-induced cyclodimerization of 5,6-dimethylidene-7-oxabicyclo[2.2.1]hept-2-ene is strongly affected by substitution at C(1) While 5,6-dimethylidene-7-oxabicyclo[2.2.1]hept–2-ene-l-methanol ( 7 ) refused to undergo [4 + 2]-cyclodimerization in the presence of [Fe₂(CO)⁹] in MeOH, 1-(dimethoxymethyl)-5,6-di-methylidene-7-oxabicyclo[2.2.1]hept-2-ene ( 8 ) led to the formation of a 1.7:1 mixture of ‘trans’ ( 19, 21, 22 ) vs. ‘cis’ ( 20, 23, 24 ) products of cyclodimerization together with tricarbonyl[C, 5,6, C-η-(l-(dimethoxymethyl)-5,6-di-methylidenecyclohexa-1,3-diene)]iron ( 25 ) and tricarbonyl[C,3,4, C-η-(methyl 5-(dimethoxymethyl)-3,4-di-methylidenecyclohexa-1,5-diene-l-carboxylate)]iron ( 26 ). The structures of products 19 and of its exo ( 21 ) and endo ( 22 ) [Fe(CO)₃(1,3-diene)]complexes) and 20 (and of its exo ( 23 ) and endo (24) (Fe(CO)₃(1,3-diene)complexes) were confirmed by X-ray diffraction studies of crystalline (1RS, 2SR, 3RS, 4RS, 4aRS, 9aSR)-tricarbonyl[C, 2,3, C-η-(1,4-epoxy-1,5-bis(dimethoxymethyl])-2,3-dimethylidene-1,2,3,4,4a,9,9a,10-octahydroanthracene)iron ( 21 ). In the latter, the Fe(CO)₃(1,3-diene) moiety deviates significantly from the usual local C_s symmetry. Complex 21 corresponds to a ‘frozen equilibrium’ of rotamers with η-alkyl, η³-allyl bonding mode due to the acetal unit at the bridgehead centre C(1).     

Mass spectrometric study of 2-azafluorenes

The fragmentation of 2-azafluorene and its methyl and phenyl-substituted derivatives was studied. It is shown that ejection of an RCN fragment (R=CH₃, C₆H₅) by the molecular ions leads to a more intense peak if R is in the 3 position of the azafluorene ring. It was established that, in contrast to the dissociative ionization of fluorene, all of the ions of which are formed from the (M-H)⁺ fragment, the fragmentation of 2-azafluorene and its derivative also takes place from the molecular ion. Randomization of the deuterium atoms attached to C₉ with the remaining hydrogen atoms was observed.Translated from Khimiya Geterotisiklicheskikh Soedinenii, No. 1, pp. 101–105, January, 1977.     

Rare direct imidation of aromatic metallacycle by reaction of CpCo(dithiolene) complex with N-halosuccinimide

The aromatic [CpCo(S₂C₂(R)(H))] (R = Ph, Me, 9-phenanthryl, H) complexes reacted with N-halosuccinimides (NXS; X = Cl, Br, I) in carbon tetrachloride at room temperature to undergo the N-succinimide substitution reaction on the dithiolene ring, but no halogenated dithiolene complex was obtained. The imidation products [CpCo(S₂C₂(R)(N-sccinimide))] were yielded up to 64% where X = I and R = 9-phenanthryl. The reaction of [CpCo(S₂C₂(Ph)(H))] with N-bromophthalimide (NBP) also gave the imidation product [CpCo(S₂C₂(Ph)(N-phthalimide))]. This is the rare direct imidation reaction to an aromatic metallacycle by NXS. The reaction of [CpCo(S₂C₂H₂)] (R = H) with NIS afforded the double imidation product. One by-product in this reaction was the dithiolene-dithiolene homo-coupling product [CpCo(S₂C₂(R))]₂ (R = Ph, Me, 9-phenanthryl). The microwave-enhanced (MW) reactions were attempted in the carbon tetrachloride solution. Although the solution temperature increased up to only 43 °C by MW irradiation, the imidation reaction worked with short reaction time.     

Synthesis and Structure of 1—Cyclopentylindenyl Lanthanide（Ⅱ）Complexes and Their Catalytic Behavior for Polymerization of Acrylonitrile

The reaction between K(1‐C₅H₉C₉H₆) and anhydrous LnCl₃ (Ln=Sm, Yb) in the molar ratio of 2:1 in THF with subsequent treatment by Na‐K alloy afforded (1‐C₅H₉C₉H₆)₂Ln‐(THF)_n(Ln=Sm, n=1; Ln=Yb, n=2), while the reaction of Sml₂ with K(1‐C₅H₉C₉H₆) in the molar ratio of 1:2 in THF gave the anionic complex K(1‐C₅H₉C₉H₆)₃Sm(THF)₃. The X‐ray structure of (1‐C₅H₉C₉H₆)₂Yb(THF)₂ showed that central metal Yb is coordinated by two cyclopentadienyl rings of 1‐cyclopentylindenyls and two oxygen atoms from two tetrahydrofuran molecules to form pseudo‐tetrahedral coordinate geometry. All these complexes are active for the polymerization of acrylonitrile.     

Indenyl and fluorenyl transition metal complexes.: IV. Reactions of 2- and 4-azafluorenes with chromium hexacarbonyl

Reactions of 2- and 4-azafluorenes (I, II) and their methyl derivatives, 3-methyl-2-azafluorene (III) and 7-methyl-4-azafluorene (IV) with chromium hexacarbonyl in a $\text{1}\text{1}$ diglyme/heptane mixture at 140°C have been studied. A N-donor complex, C₁₂H₉NCr(CO)₅ is formed in the reaction of I with Cr(CO)₆. Compounds II–IV react to give arenechromiumtricarbonyl derivatives with benzene rather than pyridine ring bound to the metal. [η⁶-(4b,5,6,7,8,9b)-4-Azafluorene]chromiumtricarbonyl (VIII) gives the corresponding hydrochloride under the action of HCl. Methyl iodide decomposes VIII to produce 4-azafluorene iodomethylate. Deprotonation of VIII with BuLi in ether at ?20°C followed by dilution with hexane leads to precipitation of the corresponding Li salt (Xb), having η⁶-structure. Methylation of Xb with methyl iodide proceeds stereospecifically to yield the exo-methyl derivative XII. Treatment of VIII with excess t-BuOK at 25°C in THF results in a mixture of η⁶-(Xa) and η⁵-anions (XI), the former predominating.     

Synthesis and Characterization of donor‐functionalized ansa‐Cyclopentadienyl‐Indenyl and ansa‐Indenyl‐Indenyl Complexes of Yttrium,Samarium, Thulium,and Lutetium

The stepwise reaction of Me₂SiCl₂ with K[C₅H₃ ^tBuMe‐3] or Li[C₉H₇] and then with K[C₉H₆CH₂CH₂‐ NMe₂‐1] followed by double deprotonation with NaH or LiBu, yields the two dimethylsilicon bridged cyclopentadienyl‐indenyl and indenyl‐indenyl donor‐functionalized ligand systems K₂[(C₅H₂ ^tBu‐3‐Me‐5)SiMe₂(1‐C₉H₅CH₂CH₂NMe₂‐3)] ( 1 ), and Li₂[(1‐C₉H₆)SiMe₂(1‐C₉H₅CH₂CH₂NMe₂‐3)] ( 2 ), respectively. Treatment of 1 with YCl₃(THF)₃, SmCl₃(THF)_1.77, TmI₃(DME)₃, and LuCl₃(THF)₃ gives the mixed ansa‐metallocenes [(C₅H₂ ^tBu‐3‐Me‐5)SiMe₂(1‐C₉H₅CH₂CH₂NMe₂‐3)]LnX (X = Cl, Ln = Y ( 3 ), Sm ( 4 ), Lu ( 5 ); X = I, Ln = Tm ( 6 )), respectively. The reaction of 2 with LuCl₃(THF)₃ yields [(1‐C₉H₆)SiMe₂(1‐C₉H₅CH₂CH₂NMe₂‐3)]LuCl ( 7 ). Compound 4 reacts with LiMe to give the corresponding alkyl derivative [(C₅H₂ ^tBu‐3‐Me‐5)SiMe₂(1‐C₉H₅CH₂CH₂NMe₂‐3)]Sm(CH₃) ( 8 ). The new complexes were characterized by elemental analyses, MS spectrometry, and NMR spectroscopy. The molecular structures of 5 and 6 were determined by single crystal X‐ray diffraction.     

Indene in a novel bonding mode in a carbonyl cluster: isolation,characterisation, and crystal and molecular structure of [HOs4(CO)9(C9H6)(C9H7)]

The reaction of [Os₃(CO)₁₂] with indene at 150°C under reflux affords the known compounds [H₂Os₃(CO)₉(C₉H₆)] (2) and [Os₄(CO)₁₂(C₉H₆)] (3). When the reaction temperature is increased to 170°C, the yield of 2 is greatly reduced, and a new tetraosmium cluster [HOs₄(CO)₉(C₉H₆)(C₉H₇)] (1) is isolated. An X-ray diffraction study of 1 has shown that one face of the Os₄ tetrahedron is capped by an indyne ligand coordinated in a μ₃-η²-− bonding mode, while the indenyl ligand (C₉H₇) is coordinated to a single Os atom in a η⁵ bonding mode through the five-membered ring.     

High resolution 13C and 1H NMR spectral analysis of 1-azafluorene

An analysis of the ¹H and ¹³C spectra of 1-azafluorene has been carried out using computer calculations and homo- and heteronuclear double resonance techniques. The ⁴J, ⁵J and ⁶J long-range coupling constants of the 9-CH₂ group protons with the protons of the pyridine and the phenylene rings have been observed and measured. The long-range J(CH) values in the ¹H coupled ¹³C spectrum have been assigned and measured on a first-order basis.     

Purines, pyrimidines, and condensed systems based on them. 17. Reactions of 6,8-dimethyl-3-chloropyrimido-[4,5-c]pyridazin-5,7(6H,8H)dione with C-nucleophiles

6,8-Dimethyl-3-chloropyrimido-[4,5-c]pyridazin-5,7(6H,8H)dione reacts with malonodinitrile, cyanoacetic ester, and nitromethane in the presence of bases to give products of nucleophilic substitution of the chlorine atom. The products containing the cyanoacetic ester and nitromethane residues exist exclusively in the chelated methylidene form in CHCl₃ and DMSO solutions. Reactions of pyridazinouracil with methylmagnesium chloride and butyllithium gave products of nucleophilic addition at C₍₄₎.For Comuunication 16, see [1].Rostov State University, Rostov-on-Don 344090, Russia Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1113–1118, August, 2000.     

Analysis of 1H NMR spectra of fluorene and azafluorenes: Long-range coupling constants

Analyses of the ¹H NMR spectra of fluorene, 2-nitrofluorene, 1-azafluorene, 2-azafluorene, 4-azafluorene, 7-nitro-4-azafluorene and 1,4-diazafuorene have been carried out using computer calculations and homo double resonance techniques. The relative signs and magnitude of the ⁴J, ⁵J and ⁶J long-range coupling constants of the 9-CH₂ group protons with the pyridine and phenylene ring protons have been measured by five- and six-spin calculations. It was established that the presence of substituents and the N heteroatom has only a very weak effect on the values and signs of these coupling constants. The usual alternating signs of long-range coupling constants involving π-electron systems were confirmed, giving negative signs for even and positive signs for odd numbers of bonds separating the coupling protons.     

Sigma-complexes in the pyrimidine series.

The alkylation of acetonyl, anionic sigma-complexes of the 5-nitropyrimidine series with geminal substitution in the 2 or 6 position is studied. Depending on the position of the geminal substitution, the C₍₅₎ or the N₍₁₎ atom is alkylated to form 2,5- or 1,6-dihydropyrimidine, respectively.See [1] for Communication 8.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1238–1243, September, 1990.     

Condensed pyridine bases. Electrophilic substitution in 1,7-dimethyl-3(2H)-benzo[b]furo[2,3-c]pyridone

Nitration, bromination, thiocyanation, and acylation of 1, 7-dimethyl-3(2H)-benzo[b]furo[2, 3-c]pyridone were investigated. It was shown that either the 4-nitro- or the 4,6-dinitro derivative is formed as a function of the nitration conditions. Bromination with bromine and thiocyanation with dithiocyanogen yields a bromo derivative at position 4. The product of substitution at the C₍₆₎, atom is obtained in acylation with acetyl chloride, and the product of substitution at atoms C₍₄₎ and C₍₆₎ is obtained with benzoyl chloride. The results of the calculations were generalized in the MNDO approximation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 534–541, April, 1996     

Calcium-mediated dearomatization, C-H bond activation, and allylation of alkylated and benzannulated pyridine derivatives

A facile and general synthetic pathway for the production of dearomatized, allylated, and C? H bond activated pyridine derivatives is presented. Reaction of the corresponding derivative with the previously reported reagent bis(allyl)calcium, [Ca(C₃H₅)₂] ( 1 ), cleanly affords the product in high yield. The range of N‐heterocyclic compounds studied comprised 2‐picoline ( 2 ), 4‐picoline ( 3 ), 2,6‐lutidine ( 4 ), 4‐tert‐butylpyridine ( 5 ), 2,2′‐bipyridine ( 6 ), acridine ( 7 ), quinoline ( 8 ), and isoquinoline ( 9 ). Depending on the substitution pattern of the pyridine derivative, either carbometalation or C? H bond activation products are obtained. In the absence of methyl groups ortho or para to the nitrogen atom, carbometalation leads to dearomatized products. C(sp³)? H bond activation occurs at ortho and para situated methyl groups. Steric shielding of the 4‐position in pyridine yields the ring‐metalated product through C(sp²)? H bond activation instead. The isolated compounds [Ca(2‐CH₂‐C₅H₄N)₂(THF)] ( 2 b ?(THF)), [Ca(4‐CH₂‐C₅H₄N)₂(THF)₂] ( 3 b ?(THF)₂), [Ca(2‐CH₂‐C₅H₃N‐6‐CH₃)₂(THF)_n] ( 4 b ?(THF)_n; n=0, 0.75), [Ca{2‐C₅H₃N‐4‐C(CH₃)₃}₂(THF)₂] ( 5 c ?(THF)₂), [Ca{4,4′‐(C₃H₅)₂‐(C₁₀H₈N₂)}(THF)] ( 6 a ?(THF)), [Ca(NC₁₃H₉‐9‐C₃H₅)₂(THF)] ( 7 a ?(THF)), [Ca(4‐C₃H₅‐C₉H₇N)₂(THF)] ( 8 b ?(THF)), and [Ca(1‐C₃H₅‐C₉H₇N)₂(THF)₃] ( 9 a ?(THF)₃) have been characterized by NMR spectroscopy and metal analysis. 9 a ?(THF)₄ and 4 b ?(THF)₃ were additionally characterized in the solid state by X‐ray diffraction experiments. 4 b ?(THF)₃ shows an aza‐allyl coordination mode in the solid state. Based on the results, mechanistic aspects are discussed in the context of previous findings.     

Formation of the unusual alkynyl carboxamide complex, C2H5N(H)C(O)CC[Co2(CO)6]CCo3(CO)9

The reaction of the cluster complex HCC[Co₂(CO)₆]CCo₃(CO)₉ with (or without) BrCCo₃(CO)₉ under Cadiot-Chodkiewicz coupling conditions gave the unusual alkynyl carboxamide complex C₂H₅N(H)C(O)CC[Co₂(CO)₆]CCo₃(CO)₉ rather than a coupled product containing two tricobalt cluster units. Steric demands imposed by the Co₃ cluster allow attack at the least hindered alkyne carbon and stabilise the formed ynamine, so allowing subsequent CO insertion. The product has been characterised by X-ray crystallography.     

Electrophilic substitution of 1-methylindeno-1H-[2,1-b]pyridine

It is shown that electrophilic substitution of 1-methylindeno-1H-[2,1-b]pyridine takes place at the C₉ atom in the case of acylation (acetylation, benzoylation, and formylation), bromination, and nitration. Data from the ¹³C NMR spectrum of this pseudoazulene confirm sp² hybridization of the C₉ atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1238–1240, September, 1982.     

Two binuclear tetracarboxylate-bridged complexes: syntheses,structures, and properties

Cu₂(C₉N₅H₉)₂(C₆H₅CO₂)₄ (1) and Zn₂(C₉N₅H₉)₂(C₁₀H₇CH₂CO₂)₄ (2) have been synthesized by hydrothermal methods with 2,4-diamine-6-phenyl-1,3,5-triazine (phdat) and aromatic carboxylic acid (benzoic acid (ba) or naphthylacetic acid (naa)) as ligands and characterized by single-crystal X-ray diffractions, elemental analyses, infrared spectra, magnetism, fluorescence spectra, and thermogravimetric analyses. In 1 and 2, the two metals are bridged by four carboxylates in paddle-wheel-shaped binuclear [M₂(CO₂)₄] units (M=Cu (1) and Zn (2)) and coordinated by one nitrogen from phdat, forming five-coordinate centers. The temperature-dependent magnetic susceptibility of 1 was obtained from 300 to 2?K, showing an anti-ferromagnetic interaction between Cu(II)'s. Compound 2 exhibits solid state fluorescence at 404?nm upon excitation at 304?nm.