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1.
《Tetrahedron》1988,44(2):405-416
The synthesis, crystal structure (7,8), conformation and dynamics of pentaspiro[2.0.2.0.2.0.2.0.2.1] hexadecane 6, pentaspiro [3.0.2.0.3.0.2.0.3.1] nonadecane 7 and pentaspiro [3.0.3.0.3.0.3.0.3.1] heneicosane 8 are described. Chair conformations have been found in the solid state (7,8) and in solution (6,7,8). The activation parameters of the chair-to-chair interconversion have been determined from bandshape analyses of exchange broadened 1H-NMR (6,7) and13 C-NMR spectra (8), respectively. The results were as follows: 6: ΔH3 = 48.9 ± 0.8 kJ/mol, ΔS3 = -20.7 ± 2.8 J/mol, grd, ΔG3298 = 55.0 ± 0.1 kJ/mol; 7: ΔH3=51.2±0.7 kJ/mol, ΔS3 = -12.0±2.4 J/mol, grd, ΔG3298 = 54.8±0.1 kJ/mol; 8: ΔH3 - 74.2±0.6 kJ/mol, ΔS3 =-21.9 ± 1.5 J/mol, grd, ΔG3298 = 80.7 ± 0.2 kJ/mol. On the basis of these values the barrier of inversion of the still unknown hexaspirane 5 is predicted to exceed 160 kJ/mol.  相似文献   

2.
The synthesis, structure and dynamics of hexaspiro[2.0.3.0.2.0.3.0.- 2.0.3.0]heneicosane 3 are described. 3 adopts a chair conformation in the crystal state but prefers a chair-to-twistboat equilibrium in solution. The activation parameters of the chair-to-chair interconversion of 3 and the closely related hexaspiro[2.0.2.0.2.0.2.0.2.0.2.0]- octadecane ([6]rotane) 4 have been determined by DNMR. Some consequences appertaining to the conformation and dynamics of other fully (cyclo-)alkylated cyclohexanes are discussed.  相似文献   

3.
S. Hirano  H. Hara  T. Hiyama  S. Fujita  H. Nozaki 《Tetrahedron》1975,31(18):2219-2227
A new preparative sequence from 2,3-polymethylene-2-cyclopentenone 5 to 2,6-polymethylenebromobenzenes 3 (n = 6, 7, 10) and 2,6-polymethylenephenyllithiums 6 has been found. The reaction of 6 with various electrophiles produces a number of new compounds to disclose the unique reactivity of the aryl C-Li moiety surrounded by the polymethylene chain. Photolysis of 3a and 3b provides transannular products 8, 10 and 11, all arising from the proximity between the aromatic bromine and the aliphatic hydrogen intraannularly opposed to be removed as HBr. Spectrometric study gives quantitative data of the dependence of the molecular geometry upon the chain length and the aromatic substituents. The energy barriers ΔGc of the conformational flipping are 17·4 kcal/mol (Tc 76·5°) for [6]metacyclophane (7a), 11·5 kcal/mol (Tc ?28°) for [7]metacyclophane (7b), ·8 kcal/mol for [10]metacyclophane (7c). The lower-energy process of the aliphatic chain in [6]metacyclophane derivatives is the pseudorotation with substituent-dependent barrier ΔGc 11·1 kcal/mol (Tc ?31·5°) for 7a, 12·4 kcal/mol (Tc ?4·5°) for 3a and 12·7 kcal/mol (Tc 1·0°) for 12a. The rather large rotational barrier is attributed to the compressed structure of each system. The benzene ring distortion of the cyclophanes is deduced from the bathochromic shift of the B-band and the diamagnetic shift of the benzene proton signals in the PMR.  相似文献   

4.
A straightforward method for the synthesis of 5-substituted tetrazolo[1,5-a]pyrido[2,3-e]pyrimidines from 2,4-diazidopyrido[3,2-d]pyrimidine in SnAr reactions with N-, O-, and S- nucleophiles has been developed. The various N- and S-substituted products were obtained with yields from 47% to 98%, but the substitution with O-nucleophiles gave lower yields (20–32%). Furthermore, the fused tetrazolo[1,5-a]pyrimidine derivatives can be regarded as 2-azidopyrimidines and functionalized in copper(I)-catalyzed azide-alkyne dipolar cycloaddition (CuAAC) and Staudinger reactions due to the presence of a sufficient concentration of the reactive azide tautomer in solution. In total, seven products were fully characterized by their single crystal X-ray studies, while five of them were representatives of the tetrazolo[1,5-a]pyrido[2,3-e]pyrimidine heterocyclic system. Equilibrium constants and thermodynamic values were determined using variable temperature 1H NMR and are in agreement of favoring the tetrazole tautomeric form (ΔG298 = −3.33 to −7.52 (kJ/mol), ΔH = −19.92 to −48.02 (kJ/mol) and ΔS = −43.74 to −143.27 (J/mol·K)). The key starting material 2,4-diazidopyrido[3,2-d]pyrimidine presents a high degree of tautomerization in different solvents.  相似文献   

5.
8,15,23,30-Tetramethyl[2.1.2.1]metacyclophane,4, is synthesised. Variable temperature 1Hmr and 13Cmr spectra indicate that 4e is the most likely conformation and that at temperatures above 50°C the molecule is fluxional (ΔG323 = 15.4 kcal/mole).  相似文献   

6.
Synthesis of a new class of cofacially oriented dipyridyl(pyridinium)lthieno[2,3-b]thiophenes with or without -CO2Et and -COMe substituents at C2, and C5 positions of thieno[2,3-b]thiophene ring was readily accomplished using a double Dieckman cyclization protocol as the key step. While C2/C5 substituted dipyridylthieno[2,3-b]thiophenes exhibited syn/anti atropisomerism at least up to 70 °C with Arrhenius energy of activation (ΔG) in the range of 17-18 kcal/mol, on the other hand unsubstituted dipyridylthieno[2,3-b]thiophene and its bis-N-quaternized salt were found to show free conformational rotation with an estimated ΔG of lower than 10 kcal/mol. Conformational energy minimization using AM1 protocol revealed a slight preference for the anti over syn isomers. Compared to the unsubstituted dipyridylthieno[2,3-b]thiophenes, higher energy barriers to rotation (3.7-5.1 kcal/mol) in substituted dipyridylthieno[2,3-b]thiophenes can be attributed to steric encumbrance resulting from -CO2Et and -COMe substituents located on the non-rotating thienothiophene platform.  相似文献   

7.
The X-ray crystal structures of 9-phenylbenz[a]azulene ( 4 ) and the corresponding non-benzannelated form, 4-phenylazulene ( 5 ), have been determined (cf. Fig.2). In contrast to 5 , the skeleton of which shows nearly equal C,C bond lengths (cf. Table 1), the seven-membered ring of 4 exhibits clearly alternating C,C bond lengths (cf. Table 1). This is in agreement with a strong accentuation of the heptafulvene substructure in 4 by the [a] benzannelation. The alternating bond lengths of 4 and of its parent structure 3 are also reflected in the corresponding variations of the 3J(H,H) and 1J(13C,13C) values of these benz[a]azulenes (cf. Tables 4 and 5). Computations on the MP2/6-31G* level as well as on the BP86/6-31G* level for azulene ( 6 ), benz[a]azulene ( 3 ), and heptafulvene ( 7 ) are in good agreement with the experimental values (cf. Tables 6–8).  相似文献   

8.
The 1,4-cycloaddition of dichloroketene to N,N-disubstituted 6-aminomethylene-b,7,8,9-tetra-hydro-5H-benzocyclohepten-5-ones afforded N,N-disubstituted 4-amino-3,3-dichloro-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones only in the case of aromatic or strong hindering aliphatic N-substitution. The adducts gave N,N-disubstituted 4-amino-3-chloro-b,7-dihydro-5H-benzo[3,4]cyclohepta[2,l-b]pyran-2-ones by dehydrochlorination with collidine. Upon chromatography on neutral alumina, two products were instead isolated in the case of usual aliphatic N-substitution (diethylamine, piperidine), namely 6-(2,2-dichloroethylidene)-6,7,8,9-tetrahydro-5H-benzocyclohepten-5-one and the dehydrochlorinated 2-pyrone; this latter was the sole product in the case of pyrrolidine substitution. The 1,4-cycloaddition of sulfene occurred readily to give N,N-disubstituted 4-amino-3,4,6,7-tetrahydro-5H-benzo[3,4]cyclohepta-[1,2-e]-1,2-oxathiin 2,2-dioxidesin the case of both aliphatic and partially aromatic N-substitution.  相似文献   

9.
Sodium [1,3-13C2]cyclopentadienide in tetrahydrofuran (THF) has been prepared from the corresponding labelled [13C2]cyclopentadiene which was synthesized from 13CO2 and (chloromethyl)trimethylsilane (cf. Scheme 10) according to an established procedure. It could be shown that the acetate pyrolysis of cis-cyclopentane-1,2-diyl diacetate (cis- 22 ) at 550 ± 5° under reduced pressure (60 Torr) gives five times as much cyclopentadiene as trans- 22 . The reaction of sodium [1,3-13C2]cyclopentadienide with 2,4,6-trimethylpyrylium tetrafluoroborate in THF leads to the formation of the statistically expected 2:2:1 mixture of 4,6,8-trimethyl[1,3a-13C2], -[2,3a-13C2]-, and -[1,3-13C2]azulene ( 20 ; cf. Scheme 7 and Fig. 1). Formylation and reduction of the 2:2:1 mixture [13C2]- 20 results in the formation of a 1:1:1:1:1 mixture of 1,4,6,8-tetramethyl[1,3-13C2]-, -[1,3a-13C2]-, -[2,3a-13C2]-, -[2,8a-13C2]-, and -[3,8a-13C2]azulene ( 5 ; cf. Scheme 8 and Fig. 2). The measured 2J(13C, 13C) values of [13C2]- 20 and [13C2]- 5 are listed in Tables 1 and 2. Thermal reaction of the 1:1:1:1:1 mixture [13C2]- 5 with the four-fold amount of dimethyl acetylenedicarboxylate (ADM) at 200° in tetralin (cf. Scheme 2) gave 5,6,8,10-tetramethyl-[13C2]heptalene-1,2-dicarboxylate ([13C2]- 6a ; 22%), its double-bond-shifted (DBS) isomer [13C2]- 6b (19%), and the corresponding azulene-1,2-dicarboxylate 7 (18%). The isotopically isomeric mixture of [13C2]- 6a showed no 1J(13C,13C) at C(5) (cf. Fig. 3). This finding is in agreement with the fact that the expected primary tricyclic intermediate [7,11-13C2]- 8 exhibits at 200° in tetralin only cleavage of the C(1)? C(10) bond and formation of a C(7)? C(10) bond (cf. Schemes 6 and 9), but no cleavage of the C(1)? C(11) bond and formation of a C(7)? C(11) bond. The limits of detection of the applied method is ≥96% for the observed process, i.e., [1,3a-13C2]- 5 + ADM→ [7,11-13C2]- 8 →[1,6-13C2]- 9 →[5,10a-13C2]- 6a (cf. Scheme 6).  相似文献   

10.
Ba[CoN]: A Low-Valency Nitridocobaltate with Angled Chains [CoN2/22?] Ba[CoN] is prepared by reaction of barium and cobalt (molar ratio Ba : Co = 1 : 2.5) in tantalum crucibles at 870°C with flowing nitrogen (1 atm) within a period of 96 h. After cooling down to room temperature (24°C/h) black single crystals of the ternary phase with a platy habit are obtained (orthorhombic, Pnma; a = 959.9(2) pm, b = 2 351.0(3) pm, c = 547.6(2) pm; Z = 20). The crystal structure of Ba[CoN] contains angled (planar) chains [CoN2/22?] which run along the [010]-direction (N? Co? N[°]: 178.5(5), 179.6(6), 180.0; Co? N? Co[°]: 82.9(6), 84.2(5), 177.1(8); Co? N[pm]: 174.6(12), 177.2(12), 181.9(13), 184.3(13), 187.1(12)). Nitrogen is in an octahedral coordination (N Ba4Co2) and is arranged in a distorted cubic close packing. Barium occupies one half of the tetrahedral holes (Ba? N[pm]: 274.8(16) ? 308.2(12)). The cis-positions of the Co-atoms at the nitrogen coordination-octahedra cause short Co? Co contacts within the chains [CoN2/22?]. Through this, Co2-units (Co? Co[pm]: 247.8(4); bridged by nitrogen) and linear Co3-groups (Co? Co [pm]: 245.5(2); Co? Co? Co[°]: 180.0; bridged by nitrogen) alternate along the chains. The crystal structure of Ba[CoN] is closely related to the Ba[NiN] type structure.  相似文献   

11.
Ab initio molecular orbital theory using basis sets up to 6-311G* *, with electron correlation incorporated via configuration interaction calculations with single and double substitutions, has been used to study the structures and energies of the C3H2 monocation and dication. In agreement with recent experimental observations, we find evidence for stable cyclic and linear isomers of [C3H2]+ ˙. The cyclic structure (, a) represents the global minimum on the [C3H2]+ ˙ potential energy surface. The linear isomer (, b) lies somewhat higher in energy, 53 kJ mol?1 above a. The calculated heat of formation for [HCCCH]+ ˙ (1369 kJ mol?1) is in good agreement with a recent experimental value (1377 kJ mol?1). For the [C3H2]2+ dication, the lowest energy isomer corresponds to the linear [HCCCH]2+ singlet (h). Other singlet and triplet isomers are found not to be competitive in energy. The [HCCCH]2+ dication (h) is calculated to be thermodynamically stable with respect to deprotonation and with respect to C? C cleavage into CCH+ + CH+. The predicted stability is consistent with the frequent observation of [C3H2]2+ in mass spectrometric experiments. Comparison of our calculated ionization energies for the process [C3H2]+ ˙ → [C3H2]2+ with the Qmin values derived from charge-stripping experiments suggests that the ionization is accompanied by a significant change in structure.  相似文献   

12.
This paper presents the data of research studies on the mechanisms, kinetics and thermodynamics of decomposition of three high-energy compounds: [1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine-3,6-diamine (TTDA), 3-amino-6-hydrazino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (TTGA) and 3,6-dinitroamino[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine (DNTT). The points of change of the reaction mechanisms under thermal effects with different intensities from 0.1 to 2000 s−1 have been established. The values of activation and induction energies for the limiting stages of decomposition have been obtained. The formation of nanostructured carbon nitride (α-C3N4) in condensed decomposition products, cyanogen (C2N2) and hydrogen cyanide (HCN) in gaseous products have been shown. Concentration-energy diagrams for the reaction products have been compiled. The parameters of heat resistance and thermal safety proved to be: 349.5 °C and 358.2 °C for TTDA; 190.3 °C and 198.0 °C for TTGA; 113.4 °C and 114.1 °C for DNTT. The energy and thermodynamic properties have also been estimated. This work found the activation energy of the decomposition process to be 129.0 kJ/mol for TTDA, 212.2 kJ/mol for TTGA and 292.2 kJ/mol for DNTT. The average induction energy of the catalytic process (Ecat) for TTGA was established to be 21 kJ/mol, and for DNTT-1500–1700 kJ/mol. The induction energy of the inhibition process (Eing) of TTDA was estimated to be 800–1400 kJ/mol.  相似文献   

13.
2D 1H-1H EXSY NMR spectroscopy show that the free energy of activation ΔG in six 3-allyl-3-borabicyclo[3.3.1]nonane derivatives is significantly higher (72–86 kJ mol?1) than that in typical allylboranes (48–66 kJ mol?1). For the first member of the series, viz., 3-allyl-3-borabicyclo[3.3.1]nonane, the activation parameters of the permanent allylic rearrangement were also determined (ΔH = 82.7±3.4 kJ mol?1, ΔS = ?11.8±10.3 J mol?1 K?1, E A = 85.5±3.4 kJ mol?1, lnA = 29.2±1.2).  相似文献   

14.
The solution structure and the aggregation behavior of (E)-2-lithio-1-(2-lithiophenyl)-1-phenylpent-1-ene ( 1 ) and (Z)-2-lithio-1-(2-lithiophenyl)ethene ( 2 ) were investigated by one- and two-dimensional 1H-, 13C-, and 6Li-NMR spectroscopy. In Et2O, both systems form dimers which show homonuclear scalar 6Li,6Li spin-spin coupling. In the case of 2 , extensive 6Li,1H coupling is observed. In tetrahdrofuran and in the presence of 2 mol of N,N,N′,N′-tetramethylethylylenediamine (tmeda), the dimeric structure of 1 coexists with a monomer. The activation parameters for intra-aggregate exchange in the dimers of 1 and 2 ( 1 (Et2O): ΔH≠ = 62.6 ± 13.9 kJ/mol, ΔS≠ = 5.8 ± 14.0 J/mol K, ΔG≠(263) = 61.1 kJ/mol; 2 (dimethoxyethane): ΔH≠ = 36.9 ± 6.5 kJ/mol, ΔS≠ = ?61 ± 25 J/mol K, ΔG≠(263) = 54.0 kJ/mol) and the thermodynamic parameters for the dimer-monomer equilibrium for 1 (ΔH°; = 26.7 ± 5.5 kJ/mol, ΔS° = 63 ± 27 J/mol K), where the monomer is favored at low temperature, were determined by dynamic NMR studies.  相似文献   

15.
In the 1 H and 13 C NMR spectra of methyl 6,7-endo,sin-dibromo-7-anti-(phenylsulfonyl)bicycle-[3.1.1]heptane-6-exo-carboxylate, H(1) and H(5) protons as well as C(1) and C(5) carbon atoms show their chemical inequivalence determined by the hindered rotation of sulfonyl and ester groups about simple C-S and C-C bonds due to the existence of donor-acceptor interaction between the carbonyl C atom and the oxygen atom of the SO2Ph group. This interaction is indicated by the single crystal X-ray diffraction study detecting the shortened intramolecular contacts (2.49 ? with the sum of the C…O van der Waals radii of 3.00 ?). Other features of the norpinane skeleton conformation and the spatial orientation of substituents in the single crystal are discussed. By 1 H NMR methods, the parameters of the dependence of molecular conformations on the temperature of DMSO-d 6 solution and the activation free energy △G c = 80.1 kJ/mol of conformational transitions are determined. By a quantum chemical DFT calculation of the potential energy surface it is revealed that the hindered rotation of the ester group makes the main contribution to the barrier of conformational transitions.  相似文献   

16.
The first hypercoordinate sila[1]ferrocenophanes [fcSiMe(2‐C6H4CH2NMe2)] ( 5 a ) and [fcSi(CH2Cl)(2‐C6H4CH2NMe2)] ( 5 b ) (fc=(η5‐C5H4)Fe(η5‐C5H4)) were synthesized by low‐temperature (?78 °C) reactions of Li[2‐C6H4CH2NMe2] with the appropriate chlorinated sila[1]ferrocenophanes ([fcSiMeCl] ( 1 a ) and [fcSi(CH2Cl)Cl] ( 1 d ), respectively). Single‐crystal Xray diffraction studies revealed pseudo‐trigonal bipyramidal structures for both 5 a and 5 b , with one of the shortest reported Si???N distances for an sp3‐hybridized nitrogen atom interacting with a tetraorganosilane detected for 5 a (2.776(2) Å). Elongated Si? Cipso bonds trans to the donating NMe2 arms (1.919(2) and 1.909(2) Å for 5 a and 5 b , respectively) were observed relative to both the non‐trans bonds ( 5 a : 1.891(2); 5 b : 1.879(2) Å) and the Si? Cipso bonds of the non‐hypercoordinate analogues ([fcSiMePh] ( 1 b ): 1.879(4), 1.880(4) Å; [fcSi(CH2Cl)Ph] ( 1 e ): 1.881(2), 1.884(2)). Solution‐state fluxionality of 5 a and 5 b , suggestive of reversible coordination of the NMe2 group to silicon, was demonstrated by means of variable‐temperature NMR studies. The ΔG of the fluxional processes for 5 a and 5 b in CD2Cl2 were estimated to be 35.0 and 37.6 kJ mol?1, respectively (35.8 and 38.3 kJ mol?1 in [D8]toluene). The quaternization of 5 a and 5 b by MeOTf, to give [fcSiMe(2‐C6H4CH2NMe3)][OTf] ( 7 a‐ OTf) and [fcSi(CH2Cl)(2‐C6H4CH2NMe3)][OTf] ( 7 b‐ OTf), respectively, supported the reversibility of NMe2 coordination at the silicon center as the source of fluxionality for 5 a and 5 b . Surprisingly, low room‐temperature stability was detected for 5 b due to its tendency to intramolecularly cyclize and form the spirocyclic [fcSi(cyclo‐CH2NMe2CH2C6H4)]Cl ( 9 ‐Cl). This process was observed in both solution and the solid state, and isolation and Xray characterization of 9 ‐Cl was achieved. The model compound, [Fc2Si(2‐C6H4CH2NMe2)2] ( 8 ), synthesized through reaction of [Fc2SiCl2] with two equivalents of Li[2‐C6H4CH2NMe2] at ?78 °C, showed a lack of hypercoordination in both the solid state and in solution (down to ?80 °C). This suggests that either the reduced steric hindrance around Si or the unique electronics of the strained sila[1]ferrocenophanes is necessary for hypercoordination to occur.  相似文献   

17.
The reaction of [2.2]paracyclophane with ferrocene in the presence of AlCl3 and Al/powder gives the new compounds [1-6-η-[2.2]paracyclophane- (η5-cyclopentadienyl)iron]+[PF6] and [1-6-η; 9-14-η-[2.2]paracyclophane- [(η5-cyclopentadienyl)iron]2]2+[PF6]2 in high yields. The species have been characterized by elemental analysis, and by 1H and 13C NMR spectroscopy.  相似文献   

18.
2-Benzoyl- 5 and 2-acetylacenaphthenone 6 , prepared from the corresponding 1-acyl-2-(1-pyrrolidinyl)-acenaphthylenes 2 and 3 , reacted with arylhydrazines 8 under acidic conditions to give the corresponding 1-arylacenaphtho[1,2-d]pyrazoles 9 and 10 . Novel heteropentalene mesomeric betaines, 5,7-dehydro-5H,7H-benzo[b]acenaphtho[1,2-e]-1,3a,6a-triazapentalenes 13 and 14 were prepared by reductive cyclization of 1-(o-nitrophenyl)acenaphtho[1,2-d]pyrazoles 9d and 10d , respectively.  相似文献   

19.
The state of water in cucurbiturils CB[6] and CB[8], which were synthesized in hydrochloric acid solutions of glycoluril and formaldehyde, was studied. The amount of water coordinated in the macrocycle cavity and on its portals was shown to depend on the moisture content of the medium, being 2.4 molecules per 1 molecule of CB[6] and 3.2 per 1 molecule of CB[8], and in CB[8] coordinated water exists in two energy states. The state with the vaporization parameters Δvap H 381.5 = 29.2±0.4 kJ mol?1 and Δvap S 381.5 = 50.7±1.0 J mol?1 K?1 coincides with the state of water in CB[6]. For another state, the vaporization parameters are Δvap H 373 = 31.7±0.5 kJ mol?1 and Δvap S 373 = 63.2±1.2 J mol?1 K?1. The number of molecules bound to the oxygen atoms of the macrocycle portals is 1.7 and 2.6 for CB[6] and CB[8], respectively.  相似文献   

20.
Methods for the synthesis of [1,2,5]oxadiazolo[3,4-c]cinnoline 5-oxides, which include the reaction of 3-nitramino-4-(R-phenyl)furazans or their O-methyl derivatives with electrophilic agents, have been developed. Unsubstituted [1,2,5]oxadiazolo[3,4-c]cinnoline 5-oxide was synthesized from 3-nitramino-4-phenylfurazan upon the action of phosphorus anhydride or oleum, as well as from O-methyl derivative of 3-nitramino-4-phenylfurazan upon the action of H2SO4, MeSO3H, CF3CO2H and BF3·Et2O, while 6-, 7-, 8-, and 9-nitro-substituted [1,2,5]oxadiazolo[3,4-c]cinnoline 5-oxides — from the corresponding 3-nitramino-4-(nitrophenyl)furazans upon the action of the H2SO4-HNO3 nitrating mixture. A suggestion has been made that an oxodiazonium ion is formed in these reactions from nitramines or their O-methyl derivatives upon the action of electrophilic agents, which is further involved into the intra-molecular reaction of electrophilic aromatic substitution (S EAr) with the aryl group. The structure of [1,2,5]oxadiazolo[3,4-c]cinnoline 5-N-oxides was confirmed by 1H, 13C, and 14N NMR spectra. Theoretical studies by the B3LYP/6-311G(d,p) method of combined molecular system (O-methylated 3-nitramino-4-phenylfurazan + [H3SO4]+) resulted in calculation of thermodynamic parameters of the sequence of cascade elementary reactions leading to the formation of [1,2,5]oxadiazolo[3,4-c]cinnoline 5-oxide.  相似文献   

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