665-46-3Relevant articles and documents
Unraveling the cation and anion effects and kinetics for ionic liquid catalyzed direct synthesis of methyl acrylate under mild conditions
Wang, Gang,Li, Zengxi,Li, Chunshan,Zhang, Suojiang
, p. 7913 - 7923 (2020/12/01)
The direct synthesis of methyl acrylate (MA) from methyl acetate and trioxane at 350-380 °C is regarded as a supplementary route for the industrial propylene oxidation process; however, it suffers from rapid catalyst deactivation. Herein, a novel ionic liquid catalyzed mild liquid-phase system was developed for the direct synthesis of MA from methyl acetate and trioxane, where N,O-bis(trimethylsilyl)acetamide (BSA) was used as a probase for α-deprotonation and enol silyl etherification of methyl acetate. The trioxane decomposition to formaldehyde and methyl acetate enolization to 1-methoxy-1-trimethylsilyloxyethene proceeded with the catalysis of [Cation]Cl/MClx (M = Cu+, Fe3+, Zn2+ and Al3+) and [Cation]F, respectively. The cations and anions were observed to have significant effects on the yield and selectivity of MA, owing to the steric hindrance, acid site category and strength confirmed by pyridine probing FT-IR characterization. As a result, up to 60.2% yield with 94.6% selectivity of MA could be achieved when [N3,3,3,3]F and [N3,3,3,3]Cl/AlCl3 with 67 mol% AlCl3 were used in the presence of BSA at 25 °C. Kinetic studies indicated that the trioxane decomposition with the activation barrier of 41.2 ± 0.3 kJ mol-1 was the rate-determining step.
A fluoride salt ion liquid synthetic method of the
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Paragraph 0264; 0265; 0266; 0267; 0268; 0269, (2016/10/10)
The invention relates to the field of organic chemical synthesis, particularly a synthesis method of a fluoride salt ionic liquid. The method comprises the following steps: adding excessive hydrofluoric acid, ammonium fluoride or ammonium bifluoride into halogenated imidazole and other raw materials, stirring in a closed environment, heating to 50-70 DEG C, and sufficiently reacting for at least 3 hours to obtain a non-dewatered fluoride salt ionic liquid; detecting, purifying and dewatering to obtain a thick liquid; and detecting the thick liquid to obtain the qualified fluoride salt ionic liquid. The method has the advantages of simple technique, no organic solvent, no waste and high end product purity.
Synthesis of Quaternary Ammonium Fluoride Salts by a Solid-Liquid Halogen Exchange Process in Protic Solvents
Dermeik, Salman,Sasson, Yoel
, p. 4827 - 4829 (2007/10/02)
Both hydrophilic and lipophilic quaternary ammomium fluoride compounds are prepared by direct exchange of the corresponding halides with solid potasium fluoride containing an optimized amount of water (4.0 mol percent).The procedure is most effective when methanol is applied as a solvent.A variety of quaternary ammonium fluorides were prepared in 75-97percent yield.
Cyclic octapeptides and pharmaceutical preparations thereof, as well as processes for their manufacture, and their use
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, (2008/06/13)
Cyclic octapeptides of the formula STR1 in which Aaa represents a radical of a straight-chained α,ω-diaminoalkanoic acid having from 4 to 7 carbon atoms, trp represents a radical L-Trp or, especially, D-Trp, or a radical derived therefrom, which carries a halogen atom in the indole nucleus, AcA represents an acyl radical Ac of an optionally substituted carboxylic acid which is positioned at the ω-amino group, or represents an amidino group or hydrogen, and AcB represents an acyl radical Ac1 of an amino acid or of an oligopeptide which is positioned at the ε-amino group, or, preferably, represents hydrogen, as well as physiologically tolerable salts and therapeutically acceptable complexes thereof can be used as antidiabetics and for the treatment of gastro-intestinal bleeding in an analogous manner to somatostatin. They can be obtained by conventional processes of peptide chemistry, especially by the cyclization of corresponding linear peptides.
