Sodium Azide In DMF Research Articles

Stereoselective Synthesis of α‐Azido Esters and α‐Amino Acid Derivatives via Matteson Homologation of Boronic Esters

AbstractMatteson homologation with sodium azide in DMF proved to be an excellent highly stereoselective tool for the synthesis of complex α‐azido and α‐amino acids. Both enantiomers are easily accessible via the choice of the chiral boronic ester auxiliary.

SYNTHESIS OF 1,2,3-TRIAZOLES BASED ON PHENACYL AZIDE DERIVATIVES VIA CLICK CHEMISTRY

Etherification of n-hexanol, n-heptanol and n-octanol with propargyl bromide in the presence of sodium hydroxide in DMF afforded the terminal alkynes (2) a, b and c. Phenacyl bromide, p-bromophenacyl bromide and p-phenylphenacyl bromide were converted to corresponding azides (4) a, b and c respectively by traditional SN2 reaction of the mentioned bromides and sodium azide in DMF. The cycloaddition of the propargyl ethers (2) with the prepared organic azides (4) using click conditions gave the target 1,4-disubstituted 1,2,3- triazoles (5)-(7) in good yields. All the synthesized triazoles were characterized by FT-IR while the compounds (5) a,b and c were characterized by 1H NMR and 13C NMR in addition to FT-IR technique.

Nitrene Cyclization of 2-(Trichloromethyl)-5-phenylpyrimidines: Application to the Synthesis of 2-(Trichloromethyl)pyrimido[4,5-b]indoles and Related Heterocycles

AbstractAn aromatic C–H nitrene insertion of 2-(trichloromethyl)pyrimidines bearing a phenyl substituent at the C-5 position is described. Treatment of 4-chloro-5-phenyl-2-(trichloromethyl)pyrimidines with sodium azide in DMF or the reflux of 4-azido-5-phenyl-2-(trichloromethyl)pyrimidines in toluene provided 2-(trichloromethyl)pyrimido[4,5-b]indole derivatives in moderate yields. Excellent yields of this heterocyclic system were obtained through the aromatic C–H insertion with the Du Bois catalyst. This is an attractive approach for synthesizing pyrimido[4,5-b]indoles with a trichloromethyl substituent in the pyrimidine moiety.

An Efficient Route for the Synthesis of 1,5‐Disubstituted Tetrazoles and their Anti‐Microbial Activity Against Salmonella Paratyphi

AbstractCarbimidothioates were synthesized by the reaction of Grignard reagents with arylisothiocyanates followed by methylation with methyl iodide. Further, these carbimidothioates were cyclized with sodium azide in DMF at 120 °C to get 1,5‐disubstituted tetrazoles, which are important class of compounds in medicinal chemistry. Hence, we evaluated the antibacterial activity against Salmonella Paratyphi bacteria. Among the series, compounds 6 a, 6 c, 6 f and 6 i effectively inhibited Solamonella Paratyphi. Compound 6 f performed well in the agar well diffusion experiment. Compound 6 i outperformed the standard drug in micro dilution assay and biofilm inhibition experiment using Crystal violet at 1 mM concentration. These studies demonstrates that active molecules are the most promising options for reducing S. paratyphi biofilm. In order to know the binding mode of the synthesized molecules, we performed molecular docking studies with protein Salmonella Paratyphi A lipopolysaccharide acetyltransferase periplasmic domain (PDB ID‐6SE1). Among the series, compounds 6 f and 6 i exhibited the most significant affinity score with 6SE1 protein.

Synthesis and Studying of the Biological Activity of Some New Coumarin-3-carboxylic Acid Heterocyclic Derivatives

This study includes the synthesis of a few different coumarin-3-carboxylic acid derivatives of 1,2,3-triazole and triazoline as a starting material. The first step involves the formation of compound (a) in absolute ethanol through the reaction of coumarin-3-carboxylic acid to thiosemicarbazide. Then compound (a) reacts with chloroacetyl chloride in the presence of triethylamine for compound forming (b). Azide derivative compound (c) was prepared with sodium azide in DMF by compound reaction (b). The heterocyclic compounds 1,2,3-triazole and triazoline derivatives (Mch1, Mch2, d, e , and f) were prepared with some unsaturated compounds such as propergyl bromide, cinnamic acid, and maleic anhydride in DMF from the reaction of compound (c). All compounds were identified by FT-IR, 1H-NMR spectrum, and C.H.N.S elemental analysis. The heterocyclic compounds were tested as an antibacterial activity with certain microorganism types. They showed good antimicrobial activity towards the investigated specific microorganisms.

Synthesis of 3,3-disubstituted 1-(1H-tetrazol-5-ylmethoxy)triaz-1-ene 2-oxides

3,3-Disubstituted 1-(tetrazol-5-ylmethoxy)triaz-1-ene 2-oxides were synthesized by heating the corresponding 1-cyanomethyl derivatives with sodium azide in DMF. The starting 1-cyanomethyl derivatives were prepared by either the reaction of chloroacetonitrile with the salts of 3,3-disubstituted 1-hydroxytriaz-1-ene 2-oxides or successive transformations of these salts to 1-methoxycarbonylmethyl and 1-carbamoylmethyl derivatives and further to 1-cyanomethyl derivatives.

Heteroaromatization with 4-Phenyldiazenyl-1-naphthol. Part IV: Synthesis of Some New Heterocyclic Compounds with Potential Biological Activity.

Synthetic azo compounds and their derivatives have been studied extensively due to their biological and pharmacological activities. Pyranopyridines, pyranopyrimidines and tetrazoles derivatives have emerged as a promising and attractive scaffold in the development of potent biological and pharmacological agents. To design a series of new benzochromeno(pyridine/pyrimidine/tetrazole) derivatives and evaluate their antimicrobial activity against some bacterial strains (Gram-positive and Gram-negative) and some fungal strains. The (E)-7-(4-chlorophenyl)-5-(phenyldiazenyl)-10-thioxo-7,9,10,11-tetrahydro-8Hnaptho[ 1,2-b]pyrano[2,3-d]pyrimidin-8-one (4) was synthesized by the reaction of 4H-naphtho[1,2-b]pyran-3- carbonitrile (3) with carbon disulfide in alcoholic potassium hydroxide solution. Reaction of 3 with sodium azide in DMF and in presence of ammonium chloride afforded 6-(phenyldiazenyl)-3-(1H-tetrazol-5-yl)-4Hbenzo[ h]chromen-2-amine (7) while with malononitrile, thiourea or urea gave chromeno[2,3-b]pyridine-9- carbonitrile (8), chromeno[2,3-d]pyrimidine-10-thione (9) and chromeno[2,3-d]pyrimidin-10-one (10), respectively. The assignment structures were established on the basis of spectral data. In this study, the antimicrobial activity of the synthesized compounds 3-12 was examined for their in vitro antimicrobial activity by using agar diffusion method such as Mueller-Hinton agar medium for bacteria and Sabouraud's agar medium for fungi. Ampicillin and mycostatine were included in the experiments as reference drugs. A series of new benzochromeno(pyridine/pyrimidine/tetrazole) derivatives were synthesized in this work. All compounds were evaluated in antimicrobial activities.

COPPER-CATALYZED 1,3-DIPOLAR CYCLOADDITION REACTION OF SPIROSOLANEDERIVED AZIDE FOR THE PREPARATION OF MODIFIED SOLASODINE ALKALOID

Modification of the steroidal alkaloid solasodine was performed by introduction of 1,2,3-triazolyl substituents at the С-6 atom of spirosolane ring system. The azidolysis of 5,6α-epoxysolasodine diacetate, formed as the major product during epoxidation of solasodine diacetate by the action of sodium azide in DMF in the presence of ammonium chloride, proceeded through the formation of 6β-azido-5α-hydroxysolasodine diacetate. The newly obtained azide was used in reactions with terminal alkynes in the presence of copper(I) bromide and N,N-diisopropylethylamine in DMF to synthesize the respective (22R,25R)-N,O-diacetyl-6β-[4-aryl-1,2,3-triazol-1-yl]-5α-hydroxyspirosolanes.

Copper-catalyzed 1,3-dipolar cycloaddition reaction of spirosolanederived azide for the preparation of modified solasodine alkaloid

Modification of the steroidal alkaloid solasodine was performed by introduction of 1,2,3-triazolyl substituents at the С-6 atom of spirosolane ring system. The azidolysis of 5,6α-epoxysolasodine diacetate, formed as the major product during epoxidation of solasodine diacetate by the action of sodium azide in DMF in the presence of ammonium chloride, proceeded through the formation of 6β-azido-5α-hydroxysolasodine diacetate. The newly obtained azide was used in reactions with terminal alkynes in the presence of copper(I) bromide and N,N-diisopropylethylamine in DMF to synthesize the respective (22R,25R)-N,O-diacetyl-6β-[4-aryl-1,2,3-triazol-1-yl]-5α-hydroxyspirosolanes.

The Study on synthesis and transformations of some of substituted 4-methylquinolin-2(1H)-ones

Some different substituted 4-methylquinolin-2(1H)-ones have been synthesized by closing corresponding (un)substituted acetoacetanildes in the presence of ionic liquid [Bmim]OH. Obtained quinolines were conveted to its 2-chloro derivatives by reaction with POCl3. Some compounds of substituted tetrazolo[1,5-a]quinolines were synthesized by acting these 2-chloro derivatives with sodium azide in DMF as solvent. The structures of obtained compounds have been confirmed by using spectroscopic methods (IR, NMR and MS)

New Polynuclear Nonfused Bis(1,3,4-Oxadiazole) Systems

In the present work, new polynuclear non-fused bis-(1,3,4-oxadiazole) compounds were obtained through Huisgen reaction of bis-(5-oxy-(1H)-tetrazoles with acid chlorides. Bis-tetrazole VIg was obtained from the 1,3-dipolar cycloaddition reaction between suberonitrile and sodium azide in DMF. The prepared compounds have been characterized by IR, 13C NMR, mass spectroscopy and elemental analysis.

A versatile synthesis of arylaminotetrazoles by a magnetic Fe@Phendiol@Mn nano‐particle catalyst and its theoretical studies

The Fe3O4 magnetic nano‐particles were modified with 1,10‐phenanthroline‐5,6‐diol and the relevant Mn complex (Fe@Phendiol@Mn) synthesized as a nano‐magnetic heterogeneous catalyst to be used for the synthesis of various arylaminotetrazoles from various arylcyanamides and sodium azide in DMF at 120 °C. Also, the nano‐catalyst characterized by different methods such as the elemental analysis (CHN), ICP, FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA, VSM and XPS. In addition, the theoretical study of the Fe@Phendiol@Mn nano‐catalyst was performed using the Gausian software. The calculated results showed that the Gibbs free energy and the standard enthalpy values are negative; therefore the complex is stable. Incidentally, the computational chemistry descriptions including the electronic chemical potential, global hardness, electrophilicity index, energy gap, global softness and electronegativity were calculated.

Microwave-assisted synthesis of poly(glycidyl azide-co-tetrahydrofuran)

The poly(glycidylazide-co-terahydrofuran) [poly(GA-THF)] or GA-THF copolymers are recognized and established as high-energy binders in explosive systems. In present study, we have developed a greener approach for the syntheses of poly(glycidylazide-co-tetrahydrofuran) copolymers using microwave (MW) irradiation technique. Polymerization of epichlorohydrin and tetrahydrofuran was carried out in the presence of borontrifluoride etherate and ethylene glycol to afford polyepichlorohydrin-tetrahydrofuran (PECH-THF) copolymer followed by its reaction with sodium azide in DMF under microwave irradiation to give poly(GA-THF). The poly(GA-THF) copolymer and their precursors were characterized by various spectral techniques such as MS, 1H-NMR, 13C-NMR, UV–visible, and FTIR. The thermal analysis was done by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Molecular weights of these copolymers were determined using GPC techniques. Morphology of these copolymers was visualized using SEM. Our experimental study shows that the microwave irradiation was effective for the second step (azidation reaction) than conventional heating for the synthesis of GA-THF copolymers. Also, the benign syntheses were tackled and explored with range of solvents. Thus, the current methodology, might advent the researchers dealing with these high-energy binder materials in future.

Synthesis of Functionalized Poly(lactic acid) Using 2-Bromo-3-hydroxypropionic Acid

Brominated poly(lactic acid) (PLB) and brominated poly(lactic acid-co-glycolic acid) (PLGB) were synthesized by acid-catalyzed melt copolyesterifications of glycolic acid and/or lactic acid with 2-bromo-3-hydroxypropionic acid, which is a brominated constitutional isomer of lactic acid. Molecular weights up to Mn = 104 Da were achieved by adding diphenyl ether to the copolymerizations (100% w/v comonomer concentration) performed at 90–130 °C in vacuo. GPCPSt underestimates the molecular weight of PLB when it contains at least approximately 6 mol % brominated units. The bromine atoms of PLB5050 (MnPSt = 5.32 × 103 Da; absolute Mn ∼ 1.70 × 104 Da) were replaced quantitatively with iodide using sodium iodide in acetone at room temperature, with a modest decrease in the molecular weight (MnPSt = 4.62 × 103 Da). PLB was also reacted with 0.25 equiv of sodium azide in DMF at 0 °C to replace the corresponding amount of bromine atoms in 88% efficiency, again with a slight decrease in the apparent molecular weight...

Water-soluble PEGylated silicon nanoparticles and their assembly into swellable nanoparticle aggregates

Water-soluble silicon nanoparticles were synthesized by grafting PEG polymers onto function- alized silicon nanoparticles with distal alkyne or azide moieties. The surface-functionalized silicon nanopar- ticles were produced in one step from the reactive high-energy ball milling (RHEBM) of silicon wafers with a mixture of either 5-chloro-1-pentyne in 1-pen- tyne or 1,7 octadiyne in 1-hexyne to afford air and water-stable chloroalkyl or alkynyl-terminated nano- particles, respectively. Nanoparticles with the x- chloroalkyl substituents were easily converted to x- azidoalkyl groups through the reaction of the Si nanoparticles with sodium azide in DMF. The azido- terminated nanoparticles were then grafted with mono-alkynyl-PEG polymers using a copper- catalyzed alkyne-azide cycloaddition (CuAAC) reac- tion to afford core-shell silicon nanoparticles with a covalently attached PEG shell. Covalently linked Si nanoparticle clusters were synthesized via the CuAAC ''click'' reaction of functional Si NPs with a,x- functional PEG polymers of various lengths. Dynamic light scattering studies show that the flexible globular nanoparticle aggregates undergo a solvent-dependent change in volume (ethanol ( dichloromethane ( tol- uene) similar in behavior to hydrogel nanocomposites.

Reaction of 3-Alkynylquinoxaline-2-carbonitriles with Sodium Azide: an Experimental and Theoretical Study

The reaction of 3-alkynylquinoxaline-2-carbonitriles with sodium azide in DMF at 60 °C leads to the formation of 4,5-disubstituted 2H-1,2,3-triazoles in 38-82% yields. The analogous reaction in toluene in the presence of AlCl3 takes place as a tandem process involving 1,3-dipolar cycloaddition of the azide ion to the nitrile group followed by 6-endo-digonal cyclization with the formation of 5-aryl-tetrazolo[1′,5′:1,3]pyrido[3,4-b]quinoxalines.

Sequential [3+2] Cycloaddition/Air Oxidation Reactions: Triazoloyl Ion Assisted Oxidative Cleavage of Alkynes

AbstractUpon treatment with sodium azide in DMF, bisalkynes undergo chemoselective [3+2] cycloaddition followed by oxidative cleavage of the other alkyne unit by atmospheric oxygen. The neighboring triazoloyl ion is found to assist the cleavage process ultimately to deliver an acid and an aldehyde.

Improved Synthesis of 5-Substituted 1H-Tetrazoles via the [3+2] Cycloaddition of Nitriles and Sodium Azide Catalyzed by Silica Sulfuric Acid

A silica supported sulfuric acid catalyzed [3+2] cycloaddition of nitriles and sodium azide to form 5-substituted 1H-tetrazoles is described. The protocol can provide a series of 5-substituted 1H-tetrazoles using silica sulfuric acid from nitriles and sodium azide in DMF in 72%–95% yield.

Telechelic Hybrid Poly(acrylic acid)s Containing Polyhedral Oligomeric Silsesquioxane (POSS) and Their Self-Assembly in Water

Telechelic (“dumbbell-shaped”) POSS-containing inorganic/organic hybrid poly(tert-butyl acrylate) (POSS-PtBA-POSS) was prepared by the combination of ATRP and the copper-catalyzed azide–alkyne “click” reaction. Telechelic bromoterminated PtBAs with different molecular weights were first prepared via ATRP using a dibromo-functionalized ATRP initiator; subsequently, the bromo groups were transformed to azido groups using sodium azide in DMF via nucleophilic substitution. The “click” coupling between azido-terminated PtBA and alkyne-functionalized POSS was successfully accomplished to afford telechelic POSS-PtBA-POSS, which is confirmed by NMR and GPC. The telechelic POSS-PtBA-POSS was then hydrolyzed to amphiphilic telechelic POSS-functional poly(acrylic acid) (POSS-PAA-POSS). The self-assembly behavior of POSS-PAA-POSS with three different molecular weights in aqueous solution at pH 8.5 was investigated by transmission electron microscopy, scanning electron microscopy, and light scattering (SLS, DLS). The ...

Synthesis of 1-Nonyl-4-[(6-Deoxy-1,2:3,4-Di-O-Isopropylidene-α-D-Galactos6-yl)oxymethyl]1H-1,2,3-Triazole Via Click Chemistry

The SN2 reaction of nonyl bromide with sodium azide in DMF afforded Nonyl azide (1).Dgalactose has been protected by acetone in acidic medium gave 1,2:3,4-di-O-isopropylidene-α-Dgalactose (2). Williamson etherfication of (2) with propargyl bromide and sodium hydroxide yielded 6-O-(2-Propynyl)-1,2:3,4-di-O-isopropylidene-α-D-galactose(3). [2+3] Cycloaddition of (3) to nonyl azide using Click conditions afforded1-Nonyl-4-[(6-deoxy-1,2:3,4-di-O-isopropylidene-αD-galactose-6-yl)oxymethyl]1H-1,2,3-triazole(4). All prepared compounds have been characterized by FT-IR , 1 H NMR and 13 CNMR.