- Preparation method of distearoyl phosphatidylethanolamine
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The invention provides a preparation method of distearoyl phosphatidylethanolamine, wherein the preparation method comprises the following steps: (1) under alkaline conditions, carrying out amino protection reaction on glyceryl phosphatidylethanolamine represented by a formula (II) and a compound containing an amino protection group to obtain an intermediate a represented by a formula (III); (2) under the action of a catalyst, carrying out acylation reaction on the intermediate a and stearic anhydride to obtain an intermediate b represented by a formula (IV); and (3) under an acidic condition,carrying out an amino protection group removal reaction on the intermediate b to obtain distearoyl phosphatidylethanolamine represented by a formula (V), wherein R in the formula (III), the formula (IV) and the formula (V) represents an amino protection group. The preparation method is simple to operate, high in product yield and easy for industrial production.
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Paragraph 0070; 0088-0093
(2021/03/30)
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- METHOD FOR SEPARATING HIGH-BOILING CARBOXYLIC ACID VINYL ESTER/CARBOXYLIC ACID MIXTURES
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The invention relates to a method for separating a mixture containing at least one carboxylic acid vinyl ester of general formula R′—C(O)O—CH═CH2 and at least one carboxylic acid of general formula R′—COOH, wherein R′ in either case can be an aliphatic group having 12 to 22 C atoms or a cycloaliphatic group having 12 to 22 C atoms, or an aromatic group having 12 to 22 C atoms, and R′ can be identical or different, characterized in that the carboxylic acid is converted to its anhydride R′—C(O)—O—C(O)—R′ and the carboxylic acid vinyl ester is subsequently separated.
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Paragraph 0035-0037
(2017/05/15)
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- Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent
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An efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.
- Rouhi-Saadabad, Hamed,Akhlaghinia, Batool
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p. 479 - 485
(2015/01/30)
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- Light-enabled synthesis of anhydrides and amides
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Recently, we have demonstrated that the photogeneration of Vilsmeier-Haack reagents is possible using only dimethylformamide (DMF) and tetrabromomethane (CBr4) in the bromination of alcohols. Extending these findings to carboxylic acid substrates has produced a mild and facile approach to the in situ formation of symmetric anhydrides, which were conveniently converted to amide derivatives in a one-pot process. The efficient protocols discussed herein are marked by use of UVA LEDs (365 nm), which have reduced the reaction times and come with a low setup cost.
- Mccallum, Terry,Barriault, Louis
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p. 2874 - 2878
(2015/03/30)
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- Use of glycerol carbonate in an efficient, one-pot and solvent free synthesis of 1,3-sn-diglycerides
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An efficient solvent-free synthesis of a variety of highly pure 1,3-sn-diglycerides (1,3-sn-diacylglycerols) in a two-step one pot process is described. Heating glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one) with fatty acid anhydrides 2a-d affords 1:1 mixtures of glycerol carbonate fatty esters 3a-3d and the corresponding fatty acids. Further heating the reaction mixtures in the presence of catalytic amounts of 1,4-diazabicyclo[2.2.2]octane (DABCO) at 195-200 °C yields highly pure 1,3-sn-diglycerides 4a-4d.
- Kargar, Mojgan,Hekmatshoar, Rahim,Ghandi, Mehdi,Mostashari, Abdoljalil
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p. 259 - 264
(2013/07/27)
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- Iron-catalyzed decarbonylation reaction of aliphatic carboxylic acids leading to α-olefins
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The catalytic decarbonylation reaction of aliphatic carboxylic acids can be carried out in the presence of an iron complex, and it proceeds smoothly to give α-olefins with high selectivity. The Royal Society of Chemistry 2012.
- Maetani, Shinji,Fukuyama, Takahide,Suzuki, Nobuyoshi,Ishihara, Daisuke,Ryu, Ilhyong
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body text
p. 2552 - 2554
(2012/03/26)
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- PROCESS FOR PRODUCTION OF OLEFIN
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The present invention provides a process for producing an olefin from a carboxylic acid having a β-hydrogen atom or a derivative thereof using the compound containing iodine and at least one metal elements selected from the group consisting of Groups 6, 7, 8, 9, 10 and 11 metals as a catalyst.
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Page/Page column 21
(2011/06/23)
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- Simple preparation of symmetrical carboxylic acid anhydrides by means of Na2CO3/SOCl2
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A convenient and general method for the synthesis of symmetrical carboxylic acid anhydrides using sodium carbonate/thionyl chloride is described. Copyright Taylor & Francis Group, LLC.
- Kazemi,Kiasat,Mombaini
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p. 3219 - 3223
(2008/02/12)
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- Mild and efficient synthesis of carboxylic acid anhydrides from carboxylic acids and triazine coupling reagents
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Anhydrides of carboxylic acids were obtained in 53%-95% yield by treatment of appropriate carboxylic acids with 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) or 2,4-dichloro-6-methoxy-1,3,5-triazine (DCMT) in the presence of N-methylmorpholine. It has been proved that synthesis proceeds via triazine active esters 3a,b, which are able to acylate carboxylate anion but not less nucleophilic carboxylic acid.
- Kaminski, Zbigniew J.,Kolesinska, Beata,Malgorzata, Marcinkowska
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p. 3349 - 3358
(2007/10/03)
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- Dabco/SOCl2, mild, and convenient reagent for the preparation of symmetrical carboxylic acid anhydrides
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Various types of carboxylic acids undergo rapid dehydration with 1,4-diazabicyclo[2.2.2]octane, dabco / thionyl chloride, under mild reaction conditions to afford symmetrical acid anhydrides in high isolated yields.
- Kazemi, Foad,Kiasat, Ali Reza
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p. 2287 - 2291
(2007/10/03)
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- Synthesis and characterization of long chain alkyl acyl carnitine esters. Potentially biodegradable cationic lipids for use in gene delivery
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A series of alkyl acyl carnitine esters (alkyl 3-acyloxy-4- trimethylammonium butyrate chloride) were synthesized as potential biocompatible cationic lipids for use in gene transfer. The physicochemical properties of the lipids, liposomes prepared from them, and their complexes with DNA were characterized by differential scanning calorimetry (DSC), particle size, potential, and surface monolayer measurements. The transition temperatures and behavior at an air-water interface for this series are similar to phosphatidylcholines with the same hydrocarbon chain length. The physical properties of the L derivatives were not significantly different from the DL derivatives. At 70 °C, the acyl chains were readily hydrolyzed at pH 7. The influence of the aliphatic chain length (n = 12-18) on transfection efficiency in vitro was determined using cationic liposomes prepared from these lipids or their mixtures with the helper lipids, dioleoylphosphatidylethanolamine (DOPE), dioleoylphosphatidylcholine, monooleoylglycerol, and cholesterol (Chol). The mixture of myristyl 3- myristoyloxy-4-trimethylammonium butyrate chloride (MMCE, 4d) with DOPE at a 1:1 molar ratio mediated the highest transfection efficiency in cell culture. The mixture of oleyl 3-oleoyloxy-4-trimethylammonium butyrate chloride (OOCE, 4f) with Chol at a 1:1 molar ratio gave the highest transfection efficiency after intravenous administration in mice. In vivo gene expression using 4f was comparable to values obtained with the best cationic lipids reported to date.
- Wang, Jinkang,Guo, Xin,Xu, Yuhong,Barron, Lee,Szoka Jr., Francis C.
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p. 2207 - 2215
(2007/10/03)
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- Synthesis of anhydrides from acyl chlorides under ultrasound condition
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A convenient and general method for the synthesis of symmetrical anhydrides under ultrasound conditions is described.
- Hu, Yulai,Wang, Jin-Xian,Li, Shihua
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p. 243 - 248
(2007/10/03)
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- Solid-liquid phase transfer and cobalt or palladium complex catalyzed synthesis of anhydrides from acyl chlorides
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Acyl chloride can efficiently be converted into anhydride under solid liquid phase transfer catalysis by using bis(triphenylphosphine)cobalt dichloride or bis (triphenylphospine)palladium dichloride as catalyst.
- Wang,Hu,Cui
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p. 3261 - 3268
(2007/10/02)
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- A NEW SYNTHESIS OF CARBOXYLIC AND CARBONIC ACID ANHYDRIDES USING PHASE TRANSFER REACTIONS
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Acyl chlorides and alkylchloroformates smoothly reacted with one molar equivalent of sodium hydroxide, using liquid-liquid phase transfer conditions to afford high yields of the corresponding symmetrical carboxylic and carbonic hemiester anhydrides.Unstable anhydrides such as 4-nitrobenzoic, 2-furoic and methacrylic anhydrides, which are otherwise difficult to obtain, were easily prepared by this method.The reaction mechanism does not seem to involve intermediate hydrolysis of half the acid chloride into the corresponding sodium carboxylate.
- Plusquellec, Daniel,Roulleau, Fabienne,Lefeuvre, Martine,Brown, Eric
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p. 2471 - 2476
(2007/10/02)
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- Carboxydiphenyl Phosphane Sulfides
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Carboxydiphenyl phosphane sulfides (C6H5)2P(S)(OC(O)R) (2) (R = CH3 2a, C2H5 2b, C17H35 2c, (CH3)3C 2d, C6H5 2e) were prepared by reacting silver salts of carboxylic acids AgOC(O)R with (C6H5)2P(S)Cl (Scheme 1) or by treating carboxylic acids with (C6H5)2P(S)Cl in the presence of triethyl amine (Scheme 2) and spectroscopically characterized.Thermal stability and stability against hydrolysis of the mixed anhydrides is unusually high. - Key words: Carboxydiphenyl Phosphane Sulfides, Thermal Stability
- Hennig, Heinz-Werner,Sartori, Peter,Steinbrecht, Ulrich
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p. 284 - 289
(2007/10/02)
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- UNE METHODE SIMPLE ET RAPIDE DE PREPARATION DES ANHYDRIDES D'ACIDES CARBOXYLIQUES A PARTIR DE LEURS CHLORURES D'ACIDES, AVEC CATALYSE PAR TRANSFERT DE PHASE
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Symmetrical anhydrides of carboxylic acids were readily obtained, and in high yields under phase transfer conditions, i.e. by reacting the appropriate acid chloride in toluene solution (containing 0.1 eq. of n-Bu4N+ Cl-), with 20percent aqueous sodium hydroxide solution.
- Roulleau, Fabienne,Plusquellec, Daniel,Brown, Eric
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p. 4195 - 4196
(2007/10/02)
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- Synthesis of fatty acid anhydrides by reaction with dicyclohexylcarbodiimide.
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A simple method is described for the preparation of caprylic, palmitic, stearic, and oleic anhydrides. Reaction of the free fatty acid and dicyclohexylcarbodiimide in carbon tetrachloride at room temperature gives the corresponding anhydrides in high yield (87-94%).
- Selinger,Lapidot
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p. 174 - 175
(2007/10/12)
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