Efficient synthesis of symmetrical bisamides catalyzed by reusable hydroxyapatite

Efficient synthesis of symmetrical bisamides is achieved by hydroxyapatite catalyst. Hydroxyapatite catalyzes the reaction between aldehydes and amides to afford bisamides at reflux conditions in 87–95% yields in acetonitrile medium. The catalyst is readily recovered and reused at least three times without loss in its catalytic activity. This method is noteworthy that, symmetrical bisamides are synthesized by fast, simple, effective, and environmentally benign heterogeneous protocol.     

Synthesis of symmetrical disulfides by reaction of fluorine-containing thiiranes with cyclic amines

Regioselective opening of the thiirane ring in fluorine-containing thioglycidyl ethers and [(perfluorobutyl) methyl]thiirane by the action of cyclic amines afforded 1,2-aminothiols which were oxidized in situ to symmetrical disulfides. The rate of formation of the latter depended on the amine basicity. According to the NMR data, the resulting disulfides were mixtures of erythro and threo diastereoisomers.     

Synthesis of fluorine-containing heterocycles based on polyfluorooxiranes and O,N,S-dinucleophiles

The methods of synthesis of fluorine-containing O, N, S-heterocyclic compounds, such as diazines, oxazines, thiazolines, oxazolines, quinoxalines, benzoxazines, benzothiazines, imidazolidines, and glycolurils, based on the reactions of perfluoro- and polyfluorooxiranes with bifunctional nucleophilic reagents, are presented in the review. Significant influence of the solvent nature on the composition and structure of the obtained compounds is demonstrated.     

Synthesis of fluorine-containing benzimidazole derivatives

Various fluorine-containing benzimidazoles were obtained by the reaction of o-phenylene-diamine, 3,4-diaminotoluene, and 1,2-diamino-4-chlorobenzene with hexafluoropropene or perfluoro(methyl vinyl ether) in DMF. A new efficient method of synthesis of 2-(1,2,2,2-tet-rafluoroethyl)benzimidazole by the reaction of o-phenylenediamine with hexafluoropropene in the presence of diethylamine or dimethylamine in ethyl acetate is developed.     

Synthesis of fluorine-containing functionalized isoxazolines

The reaction of regioisomeric fluoroalkyl-containing (3-aminovinylketones with hydroxylamine generatedin situ from hydroxylamine sulfate, afforded 5-hydroxy- or 5-amino-5fluoroalkyl-2-isoxazolines.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1306–1307, May,1996     

Synthesis of functionalized fluorine-containing trimethylsilylcarbodiimides

New functionalized polyfluorinated carbodiimides R_FN=C=NSiMe₃ were prepared by the reactions of bis(trimethylsilyl)carbodiimide with electrophilic reagents. The structures of the resulting compounds were confirmed by¹H,¹³C,²⁹Si,¹⁴N,¹⁵N, and¹⁷O NMR spectroscopy. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 775–777, April, 1999.     

Synthesis of fluorine-containing betulin esters

28-O-Fluoroacylbetulins were synthesized via acylation of betulin by fluorocarboxylic (perfluorobutyric, perfluorooctanoic, 3-fluorobenzoic, perfluorobenzoic) acid chlorides in CHCl₃ in the presence of Py. 3,28-Di-O-fluoroacylbetulins were prepared by treatment of betulin with fluorocarboxylic (trifluoroacetic, pentafluoropropionic) acid anhydrides in Py in the presence of 4-dimethylaminopyridine. 3,28-Di-O- (3-fluorobenzoyl)betulin was obtained from acylation of betulin by 3-fluorobenzoic acid in CH₂Cl₂ in the presence of N,N′-dicyclohexylcarbodiimide and 4-dimethylaminopyridine whereas acylation by perfluorobutyric acid under the same conditions gave 28-O-perfluorobutanoylbetulin.     

Synthesis, reactions, and applications of fluorine-containing multifunctional carbon compounds

The chemistry of compounds containing a carbon atom bearing three or four different labile functional groups has received little attention. These compounds should be of considerable significance in theoretical and synthetic organic chemistry. Among the compounds with multifunctional structures, those having both carbonyl and halogen groups in addition to other heteroatom groups seem especially valuable from a synthetic viewpoint. Their potential use as probes in pure and applied synthetic chemistry has not been exploited, presumably because of structural instability and a paucity of synthetic approaches. Keeping this background in mind, we focused on the synthesis of a new class of multifunctional carbon compounds in which ester carbonyl, halogen, and other heteroatom-derived functional groups are directly attached to the central carbon atom. Fluorine was chosen as the halogen because of the inherent stability of the CF bond and because of the fundamental chemical and biological interest in fluorine-containing compounds. The synthesis, reactions, and some applications of various fluorine-containing multifunctional carbon compounds are described.     

Synthesis of fluorine-containing methoxy-1,3-diketones

A method is proposed for the synthesis of fluorine-containing methoxy-1,3-diketones by hydrolysis of N-phenylaminoalkenyl ketones, produced by the reaction of aniline and the respective methoxyalkynyl ketone in dioxane. With methanol an imine is also formed, and methyl trifluoroacetate is eliminated.Institute of Chemical Kinetics and Combustion, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1390–1392, June, 1992.     

Synthesis, spectroscopic, antimicrobial, DNA binding and cleavage studies of some metal complexes involving symmetrical bidentate N, N donor Schiff base ligand

The Schiff base ligand, N,N′-bis-(4-isopropylbenzaldimine)-1,2-diaminoethane (L), obtained by the condensation of 4-isopropylbenzaldehyde and 1,2-diaminoethane, has been used to synthesize the complexes of the type [ML₂X₂] [M = Co(II), Ni(II) and Zn(II); X = Cl and OAc]. The newly synthesized ligand (L) and its complexes have been characterized on the basis of elemental analyses, mass, ¹H and ¹³C-NMR, molar conductance, IR, UV–vis, magnetic moment, CV and thermal analyses, powder XRD and SEM. IR spectral data show that the ligand is coordinated to the metal ions in a bidentate manner. The geometrical structures of these complexes are found to be octahedral. Interestingly, reaction with Cu(II) ion with this ligand undergoes hydrolytic cleavage to form ethylenediamine copper(II) complex and the corresponding aldehyde. The antimicrobial results indicate that the chloro complexes exhibit more activity than the acetato complexes. The complexes bind to CT–DNA by intercalation modes. Novel chloroform soluble ZnL₂Cl₂ complex exhibits tremendous antimicrobial, DNA binding and cleaving properties.     

Synthesis of symmetrical and unsymmetrical N,N'-diaryl guanidines via copper/N-methylglycine-catalyzed arylation of guanidine nitrate

CuI/N-methylglycine-catalyzed coupling reaction of guanidine nitrate with both aryl iodides and bromides takes place at 70-100 °C, affording symmetrical N,N'-diaryl guanidines with good to excellent yields. Unsymmetrical N,N'-diaryl guanidines can be assembled via monoarylation of guanidine nitrate with aryl iodides bearing a strong electron-withdrawing group and subsequent coupling with another aryl iodide.     

1, 4-氧硫杂萘-4, 4-二氧化物含氟衍生物的合成

以含氟的2-(2-氯-4-硝基苯磺酰基)-1-芳基乙酮为原料, 在K2CO3/TEBA/DMF体系中, 与烷基化试剂发生烷基化-环化反应。合成六种未经文献报道的1, 4-氧硫杂萘-4, 4-二氧化物的含氟衍生物,利用元素分析、IR、1H NMR、MS对其结构进行了表征。     

Synthesis,structure, and chemical property of the first fluorine-containing porphycene

[structure: see text] A pyrrolic macrocycle, beta-tetrakis(trifluoromethyl)porphycene, is the first example of a fluorine-containing porphycene. Four electron-withdrawing CF(3) substituents provide a highly distorted structure and an attractive electron-deficient nature for the porphycene framework. From the electrochemical study, it is found that the LUMO energy level for the beta-trifluoromethylporphycene is 1.24 V more stabilized compared to that for etioporphyrin. Moreover, the deprotonation of the inner N[bond]H proton in the porphycene was observed upon the addition of DBU.     

Synthesis of fluorine-containing 3-hydroxyflavanones and isoflavones

Fluorine-containing 3-hydroxyflavanones and isoflavones were synthesized by epoxidation of F-containing chalcones by hydrogen peroxide under basic conditions and subsequent intramolecular cyclization of the resulting epoxides using BF₃·Et₂O. The ratio of products depended on the presence and position of the F atom.     

Synthesis and antiviral activities of N-mono- and/or N,N'-di-carbamoyl and acyl derivatives of symmetrical diamines

N-carbamoyl and N-acyl diamine derivatives were synthesized from symmetrical diamines by their addition to iso(thio)cyanates, cleavage reaction of acid anhydride, or N-acylation by acyl chloride. (1R,2R)-1,2-Diaminocyclohexane [(1R,2R)-1], meso-1,2-diaminocyclohexane (meso-1), (1R,2R)-1,2-diphenylethylenediamine [(1R,2R)-3], or meso-1,2-diphenylethylenediamine (meso-3) were used as the starting symmetrical diamines. The target compounds synthesized herein were evaluated for antiviral activity with herpes simplex virus type 1 (HSV-1). A few derivatives of 1,2-diaminocyclohexane [(1R,2R)-7aa and cis-7b] with adamantyl group(s) showed significant antiviral activity (EC(50)=16.0, 27.0 microg/ml).     

Synthesis of a symmetrical dithiirane

The reaction of p-xylene with epichlorohydrin in the presence of aluminum chloride gave 1,4-dimethyl-2,5-bis(1-chloro-2-hydroxypropyl)benzene, which serves as the starting compound for the synthesis of the corresponding symmetrical dithiirane.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1319–1321, October, 1985.