Reactivity in solid phase. Transformations of 2,4-di-tert-butylphenol and its derivatives under elastic deformation conditions

The solid-phase transformations of 2,4-di-tert-butylphenol (1) and its 6-bromo- (5) or 6-hydroxymetyl-substituted (11) derivatives were studied. The dependence of the behavior of compounds1 and5 in solid-phase processes on the composition of the medium was found. Oxidative coupling with the participation of atmospheric oxygen as an oxidant became possible at an excess of NaOH (or in NaOH/NaCl medium). The mechanism of oxidative debromocondensation of compound 5 that involves spontaneous dehalogenation of the haloquinolide intermediate and heterolysis of the C-Br bond with the elimination of Br⁺ was proposed. It was concluded that the mechanism proposed is common to solid-phase dienone-phenol transformations. The dual reactivity of compound11, determined by the chemical hardness of the anion-catalyst, was discovered.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1499–1503, June, 1996.     

Inhibiting effect of 5-amino-5-methyluracil and its derivatives on the free-radical oxidation of 1,4-dioxane

The antiradical activity of 5-amino-6-methyluracil in the initiated radical-chain oxidation of 1,4-dioxane as a model system was studied quantitatively. The rate constant k ₇ of its reaction with the peroxyl radical of 1,4-dioxane was measured to be (5.6 ± 1.8) × 10⁵ L mol^?1 s^?1 at 333 K. The effect of the methyl substituents in the 1- and 3-positions of the uracil ring and in the amino group on the rate constant of inhibition was studied. The strengths of all N-H bonds in the 5-amino-6-methyluracil and its derivatives were calculated in the G3MP2B3 approximation and were compared with the measured rate constants of inhibition. By the example of the reaction of 5-amino-6-uracil with i-PrO ₂ ^?? , different attack pathways of the peroxyl radical at the N-H bonds of uracil were analyzed in the UB3LYP/6-311+G(d,p) approximation. The lowest activation barrier (5.8 kJ/mol) was observed for peroxyl radical attack on the (C⁵)N-H bonds. The site responsible for the inhibition activity of the compound is the amino group.     

New N-aryloxy-phthalimide derivatives. Synthesis,physico-chemical properties,and QSPR studies

Starting from N-hydroxyphthalimide 1 and the reactive fluoro- or chloro-nitroaryl derivatives 2, 3 and 4a-e (2-chloro-3,5-dinitropyridine; 3, NBD-chloride; 4a, 1-fluoro-2,4-dinitrobenzene; 4b, picryl chloride; 4c, 4-chloro-3,5-dinitrobenzotrifluoride; 4d, 2-chloro-3,5- dinitrobenzotrifluoride; 4e, 4-chloro-3,5-dinitrobenzoic acid) the corresponding N-(2-nitroaryloxy)-phthalimide derivatives 5a-e, or 6 and 7 were obtained and characterized by IR, UV-Vis ¹H-NMR and ¹³C-NMR spectroscopy. The TLC behavior and the hydrophobicity of these derivatives have been experimentally evaluated by R_M0 parameters (using RP-TLC). The experimental R_M0 parameters were compared with the calculated partition coefficient, log P. A QSPR study was also performed to establish possible correlations between the structure and physical properties (λ_max and R_M0) of compounds 5a-e, 6, and 7.      

Synthesis and properties study of novel ferrocenyl isoxazole derivatives

A synthetic procedure based on the 1,3‐dipolar cycloaddition reactions of nitrile oxides and ethynylferrocene derived from ferrocene has been developed to synthesize new ferrocenyl‐isoxazole derivatives. The stable solids were thoroughly characterized by ¹H NMR, FT‐IR, and mass spectroscopy. The structure of (η⁵‐C₅H₅) Fe (η⁵‐C₅H₄) C₃HNOC₆H₄CH₃ was determined by single‐crystal X‐ray diffraction. The electrochemical behaviors of the synthesized ferrocenyl‐isoxazole derivatives were also studied. Copyright © 2005 John Wiley & Sons, Ltd.     

λ-radiolysis of mitomycin c derivatives

The λ-Radiolysis reactions of mitomycin C ( 1 ) and its derivatives were studied in the hope of developing a radiation-induced drug (RID). The λ-radiolysis reactions were carried out in aqueous solutions under the condition where hydrated electron (e^?_aq) was generated as a principal reactive species. The competitive λ-radiolysis studies revealed that the rate constants for the reactions of 1 with e^?_aq at room temperature was 3.6 × 10¹⁰ dm³ mol^?1s^?1. Among mitomycin C derivatives, the 5H-6-alkoxyimino derivatives 11 and 12 , and compound 13 in which ring A of 1 has the 4-hydroxy-6-hydroxyimino structure cleaved to give 1 . The mechanic aspect of these λ-radiolysis reactions is discussed.     

Preparation of 2,5-disubstituted pyrimidines from vinamidinium salts and synthesis of novel disulfane derivatives

Novel pyrimidine derivatives were prepared from the reaction of 2-substituted 1,3-bis(dimethylamino)-trimethinium salts with thiourea or guanidine in the presence of ethyl-diisopropylamine in ethanol at reflux, and also some 5-substituted pyrimidine-2-thiols has been used for the synthesis of novel disulfane compounds. Infrared, ¹H NMR, ¹³C NMR, and mass spectral data confirm the molecular structures of the newly synthesized compounds. The ultraviolet spectral behavior of these compounds was examined in DMSO and the ƛ_max of these compounds was studied.     

The analysis of dyes and dye intermediates by physico-chemical methods: I. Thin-layer chromatographic and spectrophotometric behavior of some azobenzene derivatives

Thin-layer Chromatographic behavior of 14 azobenzene derivatives was studied, suitable eluents were found, and the R_f values were determined. Spectrophotometric behavior of these substances in acetonitrile was studied, as well as the influence of acids and bases on the studied spectra. The validity of the Lambert—Beer law in a concentration region from 1 × 10_?5 to 7 × 10_?5 was verified.     

Carbon-13 nuclear magnetic resonance examination of benzonorbornene derivatives. Assignment of site of aromatic ring substitution in benzonorbornen-2-ones

¹³C nuclear magnetic resonance spectra were collected for a series of 5- and 6-monoaromatic ring-substituted benzonorbornadienes and 5-, 6-, 7-, and 8-monosubstituted benzonorbornen-2-ones. ¹³C chemical shifts values were found to be useful in the differentiation of the four monosubstituted aromatic ring isomers of benzonorbornen-2-one (1). We found that the ¹³C NMR spectrum of a substituted benzonorbornen-2-one (A) could be predicted with good accuracy (R² for each aromatic carbon ≥ 0.925) from a knowledge of the ¹³C NMR spectrum of 1 and the appropriately substituted benzene. The substituents studied were NO₂, NH₂, I, CF₃, CN, OCH₃, and H. Correlation analysis showed that the carbonyl in A was effectively insulated from the ring π-system.     

2-Polyfluoroalkylchromones. 12. Nitration of 5,7-dimethyl-2-polyhaloalkylchromones and complete assignment of signals in the 1H and 13C NMR spectra of 5,7-dimethyl-2-trifluoromethylchromone and its mono- and dinitro derivatives

The nitration of 5,7-dimethyl-2-polyhaloalkylchromones affords either 5,7-dimethyl-6-nitro- or 5,7-dimethyl-6,8-dinitro-2-polyhaloalkylchromones, depending on the reaction conditions. Signals in the ¹H and ¹³C NMR spectra of the sterically hindered chromones were completely assigned using the 2D NOESY, HETCOR, and COLOC spectra. The influence of nonplanar nitro groups on chemical shifts of carbon atoms was studied. Some spectral peculiarities of the peri-methyl group were revealed. The ¹H-¹H and ¹³C-¹H spin-spin coupling constants, including the extreme six-bond long-range coupling between the protons of the Me(5) group and H(8), were determined.     

Synthesis and redox properties of bis-ferrocenylethynyl derivatives of bis(dimethylphosphinoethane)manganese

Paramagnetic Mn^II and Mn^III complexes containing two ferrocenylethynyl ligands were synthesized. Their redox reactions were studied by cyclic voltammetry and chemical methods. The structures of the resulting compounds were determined by IR, ¹H NMR, and ESR spectroscopy. The structure of the complex [(FcCC)₂Mn(dmpe)₂]⁺PF₆ ^– was established by X-ray diffraction analysis.     

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.     

Saturated heterocycles. Part 216 . Synthesis,structure and ring opening of trans-perhydro-1,4-benzoxazepin-3-one derivatives

trans-Perhydro-1,4-benzoxazepin-3-ones 2a-c were synthesized and transformed to condensed-skeleton perhydro-trans-1,4-benzoxazepines 3a,b , the thiones 4a,b , the urea derivatives 5a,b , and N-acylated compounds 6a-e . Compounds 6b,d were ring-opened by hydrochloric acid in ethanol to yield trans-2-(1-carbethoxyethoxy)-1-acylaminomethylcyclohexane derivatives 7b,d . The ¹H- and ¹³C-nmr investigation and X-ray analysis of 5b and 6c,d proved that the expected N-acylated derivatives were formed and that both rings of the trans anellated compounds have a chair conformation.     

Antitumor effects of binuclear ferrocene derivatives

On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of the mono-, bi- and poly-nuclear ferrocene derivatives ferricenium tri-iodide (1), ferricenium tetrachloroferrate (2), 1, 1′-diethylferricenium triiodide: (3), N-(ferrocenylmethyl)hexamethylenetetramine tetrafluoroborate (4), bis(ferrocenylmethyl)benzotriazolium tetrafluoroborate (5), bis(ferrocenyl-α-ethyl)benzotriazolium tetrafluoroborate (6) and bis(ferrocenylmethyl)-2-methylbenzimidazolium tetrafluoroborate (7), and the oligomer (—Fc—CH₂—Fc^+˙—CH₂—)_7–8^? (PF₆)_7–8 (8) was studied in vivo (Fc?C₁₀H₈Fe). The tumor models studied included MCH-11 (mouse sarcoma induced by methylcholantrene), P-815 (mouse mastocytoma of DBA/2 origin) and virus-induced Raucher leukemia (RLV). The cytotoxic effects of these preparations were examined against in vitro cultured normal murine cells (line L-929). The binuclear ferrocene derivatives 5, 6 and 7 inhibited the development of experimental tumors in mice. Ferricenium tri-iodide (1) was effective in Rauscher leukemia. Kinetic dependencies for most complexes had a two-phase character: the region of inhibition of tumorogenesis was followed by a region in which the complexes accelerated the development of this process. The link between the structure of compounds 1–8 and their antitumor effects is discussed.     

Preparation of dithiocarbamatecellulose derivatives and their adsorption properties for trace elements

Tosylcellulose was treated separately with aniline, benzylamine, n-butylamine and piperazine to give four different aminocelluloses which were further treated with carbon disulfide to furnish four dithiocarbamatecelluloses (AND, BZD, BUD and PID). A comparative study was made of their performance as adsorbents for several kinds of metal ions. PID, which has the highest degree of substitution of the dithiocarbamate group of the four derivatives obtained, was investigated for its adsorption behavior towards Ag⁺, As⁵⁺, Cd²⁺, Co²⁺, Cr³⁺, Cr⁶⁺, Cu²⁺, Fe³⁺, Hg²⁺, Mn²⁺, Pb²⁺, Sb⁵⁺; Se⁴⁺, Te⁴⁺ and Zn²⁺. PID showed good adsorption characteristics with relatively large capacities for Ag⁺, Cr⁶⁺, Cu²⁺, Hg²⁺, Pb²⁺ and Se⁴⁺ ranging from 9.5 to 370 mg g^-1 of resin.     

One-pot synthesis of novel polysubstituted furopyran derivatives via pseudo seven-component reaction (6 + 1) of isocyanides with bisarylidene Meldrum's acid containing ether groups

In the present study, a group of polysubstituted furopyran derivatives possessing ether spacer groups were synthesized under good-to-exceptional yields via cycloaddition of bisarylidene Meldrum's acid derivatives (1 mmol) with isocyanides (6 mmol) within dichloromethane (CH₂Cl₂) for 3 to6 hours at room temperature with no assistance from any type of catalysts. The structure of the products was then confirmed by Fourier Transform-infrared spectroscopy, ¹H-nuclear magnetic resonance spectroscopy, ¹³C-nuclear magnetic resonance spectroscopy, and elemental analysis. Moreover, the 5c , 5d , and 5f compounds exhibited favorable pharmaceutical behavior as antibacterial.     

1,6‐ and 1,7‐naphthyridines. IV. Synthesis of hydroxycarboxamide derivatives

A series of 8‐hydroxy‐1,6‐naphthyridin‐5(6H)‐one‐7‐carboxamides 1 and the isomeric 5‐hydroxy‐1,7‐naphthyridin‐8(7H)‐one‐6‐carboxamides 2 were synthesized. N‐Lactam unsubstituted compounds 1a‐c and 2a,b were obtained by alkoxide‐induced rearrangement of the corresponding quinolinimidoacetamides 3 . Compounds 1e,f and 2e,f were synthesized by heterocyclization of the corresponding quinolinamic esters 6 and 7 . Spectroscopic properties (uv, ir, ¹H and ¹³C nmr and ms) were analyzed and the proposed structures confirmed.     

Tautomerism of azine derivatives. 4. Keto-enol tautomerism of β-keto esters of the azine series

The structures of pyrazinoyl-, 3-pyridazinoyl-, 4-pyrimidoyl-, and 2-, 3-, and 4-pyridoylacetic esters were studied by means of IR, NMR, and¹H and¹³C NMR spectroscopy and quantum-chemical calculations (Pariser-Parr-Pople and CNDO/2). The effect of solvents (including strongly and weakly basic solvents) on the position of the tautomeric equilibria of these β-keto esters was studied. The o⁺ constants for the keto and enol fragments were estimated by means of quantum-chemical calculations and¹³C NMR spectroscopy. See [1] for communication No. 3. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–826, June, 1980.     

Synthesis, NMR characterization and reactivity of 1-silacyclohex-2-ene derivatives

The chloro functionality of allyldichlorosilane (HSiCl₂(C₃H₅)) and allyldichloromethylsilane (MeSiCl₂(C₃H₅)) were replaced by alkynyl groups and new compounds, allyldialkynylsilane 1 and allyldialkynylmethylsilane 2, were obtained. These silanes, which served as starting materials for the onward reactions, were purified by fractional distillation. They were further subjected to hydroboration with 9-BBN (9-borabicyclo[3.3.1]nonane) and were converted into 1-silacyclohex-2-ene derivatives 5 and 6. The competition between C≡C and C=C in the reaction was studied. The hydroborating reagent 9-BBN was expected to prefer terminal C=C bonds and to leave C≡C bond untouched. This hypothesis of preferable hydroboration was experimentally proved, and hence, 1-silacyclohex-2-ene derivatives were obtained in reasonably pure form. The reaction of allyldialkynylsilane 2 with one equivalent of 9-BBN affords 1-silacyclohex-2-ene bearing Si-C≡C-function, ready to be hydroborated further with one equivalent of 9-BBN. The obtained compound bears two C-B bonds, which are attractive synthones for further transformations. This study aims to highlight the chemistry of C-B and Si-H functional groups. All new compounds obtained were colorless air and moisture sensitive oils, and they were studied by multinuclear magnetic resonance spectroscopy (¹H, ¹³C, ¹¹B, ²⁹Si NMR) in solution.      

Synthesis of novel crown ethers. Part 1. Coumestan and coumestan analog derivatives of crown ethers

The presented ethylenedioxy compounds5a,5d,6a and6c are examples of novel cyclic ethers, while macrocyclic polyethers represent new crown ether analogues. New coumestan-crowns5a-f, derivatives of 6,7-dihydroxy-3,4-dihydro-2H-dibenzofuran-1-one and 6,7-dihydroxy-3,3-dimethyl-3,4-dihydro-2H-dibenzofuran-1-one6a-e were synthesized from the correspondingo-dihydroxy compounds3a-b,4a-b and ditosylates or dichlorides of di- or triethylene glycol in the presence of K₂CO₃, in DMF/H₂O (15/1) solutions at 65–75 °C for 35 hours. The structure of the macrocyclic ethers obtained were confirmed by¹H-NMR,¹³C-NMR, IR spectra and elemental analyses.Presented at the Sixth International Seminar on Inclusion Compounds, Istanbul, Turkey, 27–31 August, 1995.     

15N-NMR. Spectra of pterins and folic acid derivatives

¹⁵N-Chemical shifts of a series of 5, 6, 7, 8-tetrahydropterins, 7, 8-dihydropterins and pterins have been measured in acidic solution by means of a probe for 20 mm sample tubes. Included are the relevant data of folic acid (11) , 5, 6, 7, 8-tetrahydrofolic acid (5) and N (5, 10)-metheno-5, 6, 7, 8-tetrahydrofolic acid (6) . The different oxidation states are clearly relected in the chemical shifts of N (5) and N (8). Assignment of the nitrogen resonances was achieved by protonation effects (discrimination between N (1) and N (3)) and with the aid of alkyl substitution at C (6) and C(7), to distinguish between N (5) and N (8).