SYNTHESIS OF 1,2,3-TRIAZOLO-QUINOLIZIDINES BASED ON THE QUINOLIZIDINE ALKALOID LUPININE

The modification of the quinolysin alkaloid lupinine was carried out with the intro-duction of 1,2,3-triazolyl substituents for the hydroxymethylene group in the C-1 position of the quinolysin backbone. The reaction of lupinine with methanesulfochloride in the presence of triethylamine smoothly led to lupinine methanesulfonate, whose further reaction with sodium azide in DMFA led to lupinilazide. 1,3-Dipolar [4+2]-cycloaddition of the resulting azide to alkynes produced more stable 1,2,3-triazole compounds. The interaction of lupinilazide with 2-ethinylpyridine and with alcohols containing a terminal acetylene group (propargyl alcohol, 2-methylbut-3-in -2-ol or hex-5-in -1-ol) proceeded smoothly in the DMFA medium. The reactions were carried out in the presence of an aqueous solution of CuSO4 and sodium ascorbate in DMFA and allowed the corresponding 4-substituted (1S,9aR)-1H-1,2,3-triazol-1-yl to be synthesized with good yields)methyl)octahydro-1H-quinolysins. The results of studying the structural features of synthesized compounds by 1H - and 13C - NMR spectroscopy, as well as data from the two-dimensional COSY (1H-1H) and HMQC (1H-13C) spectra are presented. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra are determined. In the spectra of all synthesized new quinolizi-dinotriazoles, there is a peak of the fragmentary C10H17N ion (150-151 cu), corresponding to the cleavage of the molecule by the C-10 atom of the quinolizidine backbone.

Recent Advances in the Synthesis of Pyrroles

: Pyrroles are the most prevalent heterocyclic compounds, which are present as the basic cores in many natural products, such as vitamin B12, bile pigments like bilirubin and biliverdin, the porphyrins of heme, chlorophyll, chlorins, bacteriochlorins, and porphyrinogens. The biological activities of compounds having pyrrole analogs include antimicrobial (antibacterial, antifungal), anti-cancer (anti-cytotoxic, antimitotic), anti-tumor, anti-hyperlipidemic, anti-depressant, anti-inflammatory, antihyperglycemic, antiproliferative, anti-HIV and anti-viral activities. Accordingly, significant attention has been paid to develop competent methods for the synthesis of pyrroles with improved yields in short times. This review gives an overview of different methods for the synthesis of pyrrole using easily available precursors using the following routes. . Synthesis of monosubstituted pyrrole using 2,5-dimethoxyfuran . Synthesis of pyrrole using dialkylacetylene dicarboxylate . Synthesis of pyrroles using β-ketoester . Synthesis of pyrrole using 1,2-dicarbonyl compounds . Synthesis of pyrroles using 1,3-dicarbonyl compounds . Synthesis of pyrroles using 1,3-dicarbonyl, amine, nitro and aldehyde group . Synthesis of pyrroles using 1,4-dicarbonyl compound and amines . Synthesis of pyrrole using enones . Synthesis of pyrroles using moieties having acetylene group

A Novel Acetylene-Functional/Silicon-Containing Benzoxazine Resin: Preparation, Curing Kinetics and Thermal Properties

Benzoxazine resin has been paid more attention in the fields of aviation, electronics, automobiles and new energy industries because of its excellent comprehensive performance. Further application is limited, however, by shortcomings such as high brittleness and high curing temperature. Furthermore, higher thermal stability is imperiously demanded in special areas. Incorporating both an acetylene group and silicon into the benzoxazine monomer is a promising possible solution to improve the curing processability, thermal properties and toughness of benzoxazine. In this paper, an acetylene-functional/silicon-containing benzoxazine monomer was prepared by two-step synthesis, and acetylene-functional benzoxazine was also prepared as a comparison. FTIR and 1H NMR confirmed the molecular structure of acetylene-functional/silicon-containing benzoxazine. Differential scanning calorimetry (DSC) analysis showed that the initial and peak degradation temperatures of acetylene-functional/silicon-containing benzoxazine were decreased by 21 °C and 18 °C compared with acetylene-functional benzoxazine, respectively. The apparent activation energy of the curing reaction of acetylene-functional/silicon-containing benzoxazine was 83.1 kJ/mol, which was slightly lower than acetylene-functional benzoxazine (84.7 kJ/mol). TGA results showed that the acetylene-functional/silicon-containing benzoxazine had a higher thermal stability than acetylene-functional benzoxazine. The temperatures of 5% weight loss of acetylene-functional/silicon-containing benzoxazine were 380 °C in nitrogen and 485 °C in air, and the char yield at 1000 °C was 80% in nitrogen and 21% in air, respectively. The results of mechanical properties showed that the impact strength of acetylene-functional/silicon-containing benzoxazine was higher than acetylene-functional benzoxazine by 35.4%. The tensile and flexural strengths of acetylene-functional/silicon-containing benzoxazine were slightly higher than that of acetylene-functional benzoxazine.

Synthesis of LC Intermediate Containing Trimethyl Silyl Acetylene Group

In order to obtain the important liquid crystal intermediate with trifluoromethyl substitutent, Sonogashira coupling reaction was used to synthesize the compound. In this paper, the intermediate was synthesized by 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene (TMSA) as raw materials. During the synthesis, the optimum reaction conditions were obtained, that the mol ratio of 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene is 1:2, the reaction temperature is 30 oC, and the reaction time is 10 h.

(4′-Ethynyl-2,2′:6′,2′′-terpyridine)(2,2′:6′,2′′-terpyridine)ruthenium(II) bis(hexafluoridophosphate) acetonitrile disolvate

The title heterolepticbis-terpyridine complex, [Ru(C15H11N3)(C17H11N3)](PF6)2·2CH3CN, crystallized from an acetonitrile solution as a salt containing two hexafluoridophosphate counter-ions and two acetonitrile solvent molecules. The RuIIatom has a distorted octahedral geometry due to the restricted bite angle [157.7 (3)°] of the twomer-arrangedN,N′,N′′-tridendate ligands,viz.2,2′:6′,2′′-terpyridine (tpy) and 4′-ethynyl-2,2′:6′,2′′-terpyridine (tpy′), which are essentially perpendicular to each other, with a dihedral angle of 87.75 (12)° between their terpyridyl planes. The rod-like acetylene group lies in the same plane as its adjacent terpyridyl moiety, with a maximum deviation of only 0.071 (11) Å from coplanarity with the pyridine rings. The mean Ru—N bond length involving the outer N atomstransto each other is 2.069 (6) Å at tpy and 2.070 (6) Å at tpy′. The Ru—N bond length involving the central N atom is 1.964 (6) Å at tpy and 1.967 (6) Å at tpy′. Two of the three counter anions were refined as half-occupied.