Three-component one-pot process to propargylic amines and related amide and sulfonamide compounds: application to the construction of 2-(aminomethyl)benzofurans and indoles

An efficient palladium-copper-catalyzed three-component assembling of propargyl halides, aryl or heteroaryl halides, and secondary amines is described. A wide variety of tertiary propargylic amines were synthesized in good to excellent yields from easily accessible starting materials. This three-component assembling was also effective when using potassium phthalimide or di-tert-butyliminodicarbonate instead of secondary amines. Consequently, it provides a quick entry to N-protected propargylic amines suitable intermediates for the synthesis of primary and secondary propargylic amines. In a similar way, related compounds including propargylic amide, carbamate and sulfonamide derivatives were efficiently obtained. This catalytic domino three-component process has been applied successfully to the construction of functionalized 2-(aminomethyl)benzo[b]furan or indole derivatives of biological interest.     

Bis(ammonium) tris­(hexa­aqua­magnesium) tetra­kis(hydrogen phosphite)

The structure of the title compound, (NH₄)₂[Mg(H₂O)₆]₃(HPO₃)₄, consists of [Mg(H₂O)₆]²⁺ and (NH₄)⁺ cations and (HPO₃)²⁻ anions held together by an intricate network of hydrogen bonds involving all H atoms except for one linked directly to a P atom. The Mg²⁺ cations are octa­hedrally coordinated by six water mol­ecules. One of the Mg atoms is located on a site with 2/m symmetry, whereas the other Mg atom and the P and N atoms occupy sites with m symmetry.     

Synthesis and Biological Activities of 7‐Arylazo‐7H‐pyrazolo[5,1‐c][1,2,4] Triazol‐6(5H)‐Ones and 7‐Arylhydrazono‐7H‐[1,2,4]triazolo[3,4‐b] [1,3,4]thiadiazines

Two series of 7‐arylazo‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)pyrazolo[5,1‐c][1,2,4]triazol‐6(5H)‐ones 4 and 7‐arylhydrazono‐7H‐3‐(2‐methyl‐1H‐indol‐3‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazines 7 were prepared via reactions of 4‐amino‐3‐mercapto‐5‐(2‐methyl‐1H‐indol‐3‐yl)‐1,2,4‐triazole 1 with ethyl arylhydrazono‐chloroacetate 2 and N‐aryl‐2‐oxoalkanehydrazonoyl halides 5 , respectively. A possible mechanism is proposed to account for the formation of the products. The biological activity of some of these products was also evaluated.     

Regioselectivity in Reactions of Bis‐Hydrazonoyl Halides with Some Bifunctional Heterocycles

Bis‐hydrazonoyl chloride 1 reacts regioselectively with 3‐mercapto‐1,2,4‐triazole 2a , 2,3‐dihydro‐3‐thioxo‐1,2,4‐triazin‐5(4H)‐one 2b and 2‐mercaptobenzimidazole 2c to give the hitherto unknown annelated 2,3‐bis‐(phenylhydrazono)thiazoles 6a‐c , respectively. Reactions of 1 with the methylthio derivatives of such heterocycles afforded the annelated 3,3′‐bis‐(1,2,4‐triazoles) 11a‐c , respectively. Similar reaction of 1 with 2‐phenylamino‐4(3H)‐pyrimidinones 4 gave 2,3‐bis(phenylhydrazono)imidazo[1,2‐a]pyrimidin‐5(1H)‐ones 16 . Oxidation of 6c yielded the corresponding bis(phenylazo) derivative 15 . The regiochemistry of the studied reactions is discussed.     

n-Hexane cracking over heteropoly acids, 3. Silica supported heteropoly acids

Silica supported heteropoly acids are active in n-hexane cracking, while the pure compounds (except H₃PW₁₂O₄₀) are inactive. This result is explained by a partial transformation of H₆P₂W₁₈O₆₂ and H₆P₂W₂₁O₇₁ (H₂O)₃ into H₃PW₁₂O₄₀. In the case of H₄SiW₁₂O₄₀, the polyanion in interaction with silica leads to superacidic species upon thermal treatment.

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, , -, ( H₃PW₁₂O₄₀) . H₆P₂W₁₈O₆₂ H₆P₂W₂₁O₇₁ (H₂O)₃ H₃PW₁₂O₄₀. H₄SiW₁₂O₄₀ , , .

     

Solid-liquid equilibria and purity determination for binary n-alkane + naphthalene systems

Mixtures of heavy aromatics with high aliphatics are important in the formation of asphaltenes in the oil industry.This work reports binary solid-liquid equilibria for naphtalene + eicosane, +pentacosane, +hexatriacontane mixtures by differential scanning calorimetry. Results are compared with those from modified UNIFAC (Larsen and Gmehling versions) and ideal predictions. Finally, we determine the purity according to van’t Hoff equation. Results are in good agreement with values given by ultraviolet spectrophotometry.     

Determination of the Kinetic and Thermodynamic Parameters of Adsorption Processes by a Volume Step Thermal Method

A volume step method measuring the pressure and the adsorbent temperature of an adsorbent-adsorbate system has been developped. It is shown that this method allows the determination of all the relevant parameters of an adsorption process, kinetic as well as thermodynamic in case of Linear Driving Force mass transfer. The method for determining the parameters can be extended to the case of diffusive mass transfer if the mass transfer kinetics is faster than the heat transfer kinetics. An example is given, showing the determination of the diffusion coefficient of carbon dioxide in NaX zeolite pellets and the change of the diffusion coefficient and of the isosteric heat of adsorption when the adsorbent is not fully dehydrated.     

Rational design of biocompatible IPNs hydrogels containing carboxymethyl starch and trimethyl chitosan chloride with high antibacterial activity

Cellulose - Antimicrobial hydrogels have enticed a major concern for repairing soft tissues, particularly prohibiting bacterial infections that are frequently accompanied by impaired wound healing....     

FL-MAC-RDP: Federated Learning over Multiple Access Channels with Rényi Differential Privacy

International Journal of Theoretical Physics - Federated Learning (FL) is a promising paradigm, where the local users collaboratively learn models by repeatedly sharing information while the data...