Optimization of [Bmim][HSO4]-Catalyzed Transesterification of Camelina Oil

1-Butyl-3-methylimidazolium hydrogen sulfate ([Bmim][HSO₄]) is utilized to catalyze transesterification of camelina oil with methanol. The major compositions of camelina biodiesel are saturated fatty acid esters (C16:0, C18:0), monounsaturated, and polyunsaturated fatty acid esters (C18:2, C18:3). The effects of reaction temperature, reaction time, M_methanol:M_{Camelina oil}, and M_[Bmim][HSO4]:M_{Camelina oil} on biodiesel production are investigated in detail, and a general mathematical model is developed to well predict the biodiesel yield. Also, [Bmim][HSO₄] is thermally stable to recycle for four times with a high biodiesel yield. The fuel properties of camelina biodiesel are all comparable to the American Society for Testing Materials (ASTM) standards.     

Synthesis of 2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane Using Melaminium‐tris(hydrogensulfate) by a Simple One‐Pot Nitration Procedure

A highly efficient protocol for the synthesis of 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) in the presence of melaminium‐tris(hydrogen sulfate) as a solid acid is described.     

Preparation of ε‐HNIW by a One‐Pot Method in Concentrated Nitric Acid from Tetraacetyldiformylhexaazaisowurtzitane

ε‐HNIW was prepared by a one‐pot method in concentrated nitric acid from tetraacetyldiformylhexaazaisowurtzitane (TADFIW). γ‐HNIW was firstly obtained, then γ‐HNIW was directly transformed to ε‐HNIW in the solution in which nitration reaction occurred. The acid number of ε‐HNIW prepared by the method mentioned above is less than 0.2‰, yield of ε‐HNIW is up to 91%, and the purity of ε‐HNIW is up to 99.5%. Because steps of filtration and drying of γ‐HNIW were omitted, the process by which ε‐HNIW was prepared simplified greatly.     

Oxidative Desulfurization of Model Diesel Using a Fenton‐Like Catalyst in the Ionic Liquid [Dmim]BF4

A Fenton‐like catalyst prepared from tetrabutylammonium chloride and ferric trichloride was characterized by Fourier transform infrared, UV‐vis and Raman spectroscopy. The catalyst (C₄H₉)₄NFeCl₄ (TBAFeCl₄) in an extraction and catalytic oxidative desulfurization (ECODS) system containing H₂O₂ and the ionic liquid (IL) 1‐decyl‐3‐methylimidazolium tetrafluoroborate ([Dmim]BF₄) exhibited high catalytic activity for the removal of dibenzothiophene (DBT) in model diesel. Desulfurization with the Fenton‐like catalyst TBAFeCl₄ in ECODS involves the structural distortion of DBT via polarization of the IL and its subsequent oxidation. The catalytic system could be recycled multiple times without significant decrease in desulfurization activity due to the high stability of the system.     

离子液体[C4mim][PF6]与N, N-二甲基甲酰胺二元混合物在298.15 K～318.15 K的密度和粘度

Viscosities and densities for 1-butyl-3-methylimidazolium hexafluorophosphate （[C4mim][PF6]） and N, N-dimethylformamide （DMF） binary mixtures have been measured at the temperature range from 293.15 K to 318.15 K. It is shown that the viscosities and densities decrease monotonously with temperature and the content of DMF. Various correlation methods including Arrhenius-like equation, Sedclon et al.＇s equation, Redlich-Kister equation with four parameters, and other empirical equations were applied to evaluate these experimental data. A model based on an equation of state Ior estimating the viscosity of mixtures containing ionic liquids were proposed by coupling with the excess Gibbs free energy model of viscosity, which can synchronously calculate the viscosity and the molar volume. The results show that the model gives a deviation of 8.29% for the viscosity, and a deviation of 1.05% for the molar volume when only one temperature-independent adjustable parameter is adopted. The correlation accuracy is further improved when two parameters or one temperature-dependent parameter is used.     

Solvent-Free One-Pot Synthesis of 1,8-Dioxo-Decahydroacridines by a [Et3NH][HSO4] Catalyzed Multicomponent Reaction

ABSTRACT

[Et₃NH][HSO₄] has been used as an effective catalyst for one-pot, three-component condensation of an aromatic aldehyde, 5,5-dimethyl-1,3-cyclohexanedione and ammonium acetate for the synthesis of 1,8-dioxo-decahydroacridines under solvent-free conditions. The present methodology offers several advantages, such as high yields, short reaction times, mild condition, and a recyclable catalyst with a very easy work-up.     

1‐Butyl‐3‐methylimidazolium Tetrafluoroborate ([Bmim]BF4) Ionic Liquid: A Novel and Recyclable Reaction Medium for the Synthesis of vic‐Diamines

Aziridines undergo ring opening smoothly with various arylamines in 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF₄) or 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim]PF₆) ionic liquids under mild and neutral conditions to afford the corresponding vicinal‐diamines in excellent yields with high regioselectivity. The recovered activated ionic liquids are recycled for four to five runs with no loss of activity.     

Fourier Transform Raman Spectroscopy of the Four Crystallographic Phases of α, β, γ and ε 2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazatetracyclo[5.5.0.05,9.03,11]dodecane (HNIW,CL‐20)

Fourier transform Raman Spectroscopy (Nd : YAG laser at 1064 nm) was used to characterize the four stable phases of 2,4,6,8,10,12‐Hexanitro‐2,4,6,8,10,12‐hexaazatetracyclo[5.5.0.0^5,9.0^3,11]dodecane (HNIW, CL‐20). Raman spectra are reported over the region from 0–4000 cm⁻¹_, relative to the laser line. A tentative assignment of the most predominant Raman peaks was made with the aid of QM calculations at the B3LYP/6‐31G(d) level. A method for detecting polymorphic impurities in ε‐CL‐20 was also developed. The detection level for polymorphic impurities was determined to be below 2%. A method for producing γ‐CL‐20 is also presented.     

[TMBSA][HSO4] Ionic Liquid as Novel Catalyst for the Rapid Acetylation of Alcohols, Hydroxyesters and Phenols under Solvent-free Conditions

Tri-methylammonium-butane sulfonate (TMBSA) ionic liquid (IL) catalyzed efficiently acetylation of acetic anhydride with various alcohols, hydroxyesters and phenols, under solvent-free conditions was described as a novel method. [TMBSA][HSO₄] ionic liquid (1.0 mol%) is able to promote quantitative acetylation at low temperature, in high conversion and selectivity (≥95%). The process is highly effective, environmentally benign, and very selective. Furthermore, [TMBSA][HSO₄] ionic liquid was conveniently separated with the products and easily recycled to catalyze acetylation reaction again with excellent yields.     

Development of Quantitative Analytical Methods to Measure the Polymorphic Composition of CL20 (Hexanitrohexaazaisowurtzitane – HNIW) with FTIR‐NIR or FTIR‐MIR Spectroscopy using PLS Regression

CL20 (HNIW=Hexanitrohexaazaisowurtzitane), is an energetic molecule that presents four polymorphs (called alpha (α), beta (β), gamma (γ), and epsilon (ε)). Industry is focused to synthesize the ε‐form. For them, it is very important to get an analytical method to quantify the concentration of the ε‐form, which has the best energetic performance. The aim of this work is to develop a quantitative analytical method to measure the polymorphic composition of CL20 using FTIR (mid IR and near IR, MIR/NIR) spectroscopy with PLS regression.     

One‐Pot Synthesis of Biaryl Lactones by Sonogashira Cross‐Coupling Reactions of 4‐Chloro‐3‐formylcoumarin and Subsequent Domino [5+1] Cyclization/Deacetylation Reactions with 1,3‐Dicarbonyl Compounds

Biaryl lactones were prepared by a new palladium(0) and base‐catalyzed one‐pot reaction of 4‐chloro‐3‐formylcoumarin with alkynes and 1,3‐dicarbonyl compounds.     

Catalyst‐Free Domino Reaction of 1‐Acryloyl‐1‐N‐arylcarbamylcyclopropanes with Amines: One‐Pot Approach to 2,3,6,7‐Tetrahydro‐1H‐pyrrolo[3,2‐c]pyridin‐4(5H)‐ones

A facile one‐pot, catalyst‐free reaction has been developed for the synthesis of 2,3,6,7‐tetrahydro‐1H‐pyrrolo[3,2‐c]pyridin‐4(5H)‐ones from readily available 1‐acryloyl‐1‐N‐arylcarbamylcyclopropanes and amines using a domino ring‐opening/cyclization/aza‐addition sequence.

     

The Use of theTrifluoroacetyl Protecting Group in the Synthesis of Mono‐ (4) and Di‐Amines (4,10) in the Polynitrohexaazaisowurtzitane Series

The first rational synthesis of the mono‐amine 2,6,8,10,12‐pentanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (II) and the di‐amine 2,6,8,12‐tetranitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (III) is described. Both syntheses exploit the selectivity, under nitrolysis conditions, between an N‐acetyl group and an N‐trifluoroacetyl group, and the ease with which an N‐trifluoroacetyl group can be hydrolytically removed.     

Rhodium Acetate Dimer Immobilized in 1‐Butyl‐3‐methylimidazolium Hexafluorophosphate Ionic Liquid: a Novel and Recyclable Catalytic System for the Cyclopropanation of Alkenes

Alkenes undergo smooth cyclopropanation with ethyl diazoacetate using a catalytic amount of rhodium acetate dimer, Rh₂(OAc)₄, immobilized in the air‐ and moisture‐stable 1‐butyl‐3‐methylimidazolium hexafluorophosphate ionic liquid, [bmim]PF₆, to afford cyclopropanecarboxylates in excellent yields with high trans‐selectivity. The recovery of the catalyst is facilitated by the hydrophobic nature of [bmim]PF₆. The recovered ionic liquid containing Rh₂(OAc)₄ can be reused for three to five subsequent runs with only a gradual decrease in activity.     

Efficient and Eco‐Friendly Process for the Synthesis of Bis(1H‐indol‐3‐yl)methanes using Ionic Liquids

Indoles react smoothly with carbonyl compounds in 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF₄) or 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim]PF₆) ionic liquids under mild reaction conditions to afford the corresponding bis‐indolylmethanes in excellent yields. These ionic liquids can be recovered and recycled in subsequent reactions without any apparent loss of activity.     

[4+2] Cycloaddition of ortho‐Quinone Methides Promoted by Ionic Liquids: an Efficient and Mild Protocol for the Synthesis of Tetrahydropyranobenzopyrans

The stereoselective synthesis of trans‐annelated pyrano[3,2‐c]benzopyrans has been achieved by intramolecular [4+2] cycloaddition of o‐benzoquinone methides that are generated in situ from o‐hydroxybenzaldehydes and unsaturated alcohols using an air‐ and moisture‐stable ionic liquid, i.e., 1‐butyl‐3‐methylimidazolium tetrafluoroborate [bmim]BF₄ under mild and neutral conditions.     

A New Entry for Short and Regioselective Synthesis of [1,2,4]Triazolo[4,3‐b][1,2,4]‐triazin‐7(1H)‐ones

Reaction of benzenediazonium chloride with active [1,2,4]triazin‐3‐ylthio‐methylene compounds 3 afforded the azo coupling products 5 , which yielded [1,2,4]triazolo[4,3‐b][1,2,4]triazin‐7(1H)‐ones 8 upon treatment with sodium ethoxide in ethanol. The latter products 8 were characterized on the basis of alternate synthesis and spectral data. The mechanism of formation of 8 and the regiochemistry of the studied reactions are discussed.     

N,N,N′,N′‐Tetramethylchloroformamidinium Chloride‐Mediated Cyclizations of β‐Oxo Amides: Facile and Divergent One‐Pot Synthesis of Substituted 2H‐Pyrans, 4H‐Pyrans and Pyridin‐2(1H)‐ones

An efficient and divergent one‐pot synthesis of substituted 2H‐pyrans, 4H‐pyrans and pyridin‐2(1H)‐ones from β‐oxo amides based on the selection of the reaction conditions is reported. Mediated by N,N,N′,N′‐tetramethylchloroformamidinium chloride, β‐oxo amides underwent intermolecular cyclizations in the presence of triethylamine at room temperature to give substituted 2H‐pyrans in high yields, which could be converted into substituted 4H‐pyrans in the presence of sodium hydroxide in ethanol at room temperature, or into substituted pyridin‐2(1 H)‐ones under reflux.     

Binary copolymerization of 4‐methyl‐1,3‐pentadiene with styrene,butadiene and isoprene catalysed by a titanium [OSSO]‐type catalyst

Binary copolymerization of 4‐methyl‐1,3‐pentadiene (4MPD) with styrene, butadiene and isoprene promoted by the titanium complex dichloro{1,4‐dithiabutanediyl‐2,2′‐bis[4,6‐bis(2‐phenyl‐2‐propyl)phenoxy]}titanium activated by methylaluminoxane is reported. All the copolymers are obtained in a wide range of composition and the molecular weight distributions obtained from gel permeation chromatographic analysis of the copolymers are coherent with the materials being copolymeric in nature. The copolymer microstructure was fully elucidated by means of ¹H NMR and ¹³C NMR spectroscopy. Differential scanning calorimetry shows an increase of glass transition temperature (T_g) with the amount of 4MPD in the copolymers with butadiene and isoprene, while in the copolymers with styrene T_g is increased on increasing the amount of styrene. © 2016 Society of Chemical Industry