Pyrroles from ketoximes and acetylene. 30. The synthesis of 3-alkyl-2-arylpyrroles

Conditions were found for the synthesis of 3-alkyl-2-arylpyrroles using the Trofimov reaction at 50–70 °C both at elevated and atmospheric pressure. O-Vinyloximes and 3H-5-hydroxy-4,5-dihydropyrroles were isolated as intermediates.Communication 29, see ref. [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1501–1505, November, 1985.     

Base-catalyzed dehydration of aldoximes in dimethyl sulfoxide

Conclusions A convenient method is proposed for the alkaline dehydration of aldoximes into nitriles in the presence of KOH in dimethyl sulfoxide at 140°.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 690–691, March, 1976.     

General route to symmetric and asymmetric meso-CF3-3(5)-aryl(hetaryl)- and 3,5-diaryl(dihetaryl)-BODIPY dyes

A general efficient route to hitherto inaccessible symmetric and asymmetric meso-CF(3)-BODIPY dyes has been developed. The key stages include the reduction of available 2-trifluoroacetylpyrroles to the corresponding alcohols which are further condensed with pyrroles. The method allows the BODIPY with 3(5)aryl(hetaryl) and 3,5-diaryl(hetaryl) substituents to be readily assembled. The BODIPY dyes synthesized fluoresce (Φ(f) = 0.56-1.00) in the 560-680 nm region.     

Copolymerization of N-vinylpyrrole-2-carbaldehydes with styrene, N-vinylpyrrolidone, and ethylene glycol vinyl glycidyl ether

Polyfunctional reactive copolymers of N-vinylpyrrole-2-carbaldehydes with styrene, N-vinylpyrrolidone, and ethylene glycol vinyl glycidyl ether are synthesized in the presence of AIBN (2 wt %, 80°C, 50 h) with a yield of up to 98% and a molecular mass of up to 4800. The copolymers show paramagnetic behavior (N = 2.0 × 10¹⁵?2.0 × 10¹⁷ g^?1) and possess the properties of organic semiconductors (σ = 0.9 × 10^?11–2.8 × 10^?7 S/cm after doping with I₂).     

A highly selective fluorescent sensor for fluoride anion based on pyrazole derivative: Naked eye “no–yes” detection

A new pyrazole-based fluorescent sensor, 5-amino-3-(5-phenyl-1H-pyrrol-2-yl)-1H-pyrazole-4-carboxamide (compound 1), was studied for fluoride anion (F^?) detection in organic or water-containing solution. This compound displayed both changes in UV–vis absorption and fluorescence emission spectra upon addition of F^?. With increasing of F^?, blue emission intensity increases drastically and reaches saturation with 607-fold enhancement at 424 nm. The results indicate that compound 1 has highly selectivity for fluoride detection over other anions, such as Cl^?, Br^?, I^?, HSO₄^?, H₂PO₄^? and AcO^? in DMSO or aqueous DMSO solutions. ¹H NMR titration and other experiments confirm that the sensing process is mainly from the deprotonation of the pyrazole–NH in compound 1.     

Specific Heat and Thermal Expansion of Triglycine Sulfate–Porous Glass Nanocomposites

The effect of restricted geometry on specific heat capacity and thermal expansion of the triglycine sulfate (TGS)–borosilicate glass composites have been studied first. A decrease in the entropy and temperature of the P2₁ ? P2₁/m phase transition in the TGS component with decreasing the glass matrix pore diameter at the invariable specific heat and thermal expansion coefficient has been observed. The estimates are indicative of the minor effect of internal pressure on the TGS pressure coefficient dT_C/dp in the composites.