- Improved synthesis and low-temperature performance of a series of saturated α-branched fatty acids
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Five saturated α-branched fatty acids, also known as Guerbet acids, including α-propylhexyl acid (G 1 ), α-butylhexyl acid (G 2 ), α-propyloctyl acid (G 3 ), α-butyloctyl acid (G 4 ), and α-hexyloctyl acid (G 5 ), were synthesized in high yields by four-step reaction. Colorless, almost odorless, and oily products were obtained with high purity, whose structures were confirmed by GC, 1H/13C NMR, and ESI-MS characterization. G 1, G 3, and G 4 had pour points lower than -60 °C, while G 2 and G 5 showed higher pour points (-42 °C and 6 °C, respectively) because of their molecular symmetry. Considering the low-temperature properties, G 1, G 3, G 4, and even G 2 held great potential applications in the lubricant and oilfield.
- Jiang, Yang,Hu, Wenjing,Xu, Jian,Li, Jiusheng
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p. 2359 - 2363
(2017/10/06)
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- Method for preparing Guerbet acids by taking malonate as raw material
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The invention discloses a method for preparing Guerbet acids by taking malonate as a raw material. The method comprises the following steps: using the malonate as the raw material, and carrying out alkylation reaction under the action of alkali to obtain dialkyl malonate; sequentially carrying out hydrolysis reaction and decarboxylic reaction on obtained dialkyl malonate to obtain the Guerbet acid, wherein the malonate is dimethyl malonate or diethyl malonate; the alkali of the alkylation reaction is selected from one or more of potassium carbonate, sodium hydroxide, potassium hydroxide, sodium methylate and sodium ethoxide; an alkylating reagent is haloalkane with 2 to 20 carbons. According to the method disclosed by the invention, the Guerbet acids are prepared by taking the malonate as the raw material for the first time; related three reactions are easily operated, high temperature or high pressure is not needed, and high yield is realized; by means of the alkylation reaction disclosed by the invention, a main chain structure and a branched chain structure of the Guerbet acids can be flexibly regulated and controlled, and further the Guerbet acids with different properties are obtained.
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Paragraph 0034
(2017/08/29)
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- Use of ethyl (benzothiazol-2-ylsulfonyl)acetate for malonic ester-type syntheses of carboxylic acids and esters
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A new methodology for the synthesis of substituted carboxylic acids is described. Alkylation of either ethyl (benzothiazol-2-ylsulfonyl)acetate or ethyl 2-(benzothiazol-2-ylsulfonyl)propionate was achieved with alkyl halides and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dichloromethane solution. These products were then desulfinated and hydrolysed in one-pot under mild conditions to give substituted acetic acids in good-to-excellent yields.
- Hussein, Waleed M.,McGeary, Ross P.
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p. 1222 - 1227
(2014/10/16)
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- Swallowtail porphyrins: Synthesis, characterization and incorporation into porphyrin dyads
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The incorporation of symmetrically branched tridecyl (" swallowtail") substituents at the meso positions of porphyrins results in highly soluble building blocks. Synthetic routes have been investigated to obtain porphyrin building blocks bearing 1-4 swallowtail groups. Porphyrin dyads have been synthesized in which the zinc or free base (Fb) porphyrins are joined by a 4,4′-diphenylethyne linker and bear swallowtail (or n-pentyl) groups at the nonlinking meso positions. The swallowtail-substituted Zn 2- and ZnFb-dyads are readily soluble in common organic solvents. Static absorption and fluorescence spectra and electrochemical data show that the presence of the swallowtail groups slightly raises the energy level of the filled a2u(π) HOMO. EPR studies of the π-cation radicals of the swallowtail porphyrins indicate that the torsional angle between the proton on the alkyl carbon and p-orbital on the meso carbon of the porphyrin is different from that of a porphyrin bearing linear pentyl groups. Regardless, the swallowtail substituents do not significantly affect the photophysical properties of the porphyrins or the electronic interactions between the porphyrins in the dyads. In particular, time-resolved spectroscopic studies indicate that facile excited-state energy transfer occurs in the ZnFb dyad, and EPR studies of the monocation radical of the Zn2-dyad show that interporphyrin ground-state hole transfer is rapid.
- Thamyongkit, Patchanita,Speckbacher, Markus,Diers, James R.,Kee, Hooi Ling,Kirmaier, Christine,Holten, Dewey,Bocian, David F.,Lindsey, Jonathan S.
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p. 3700 - 3710
(2007/10/03)
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