- Synthetic method of propiolic acid
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The invention discloses a synthetic method of propiolic acid. The method comprises the following steps of: putting calcium carbide, a hydrogen donor, a solvent, a catalyst and an auxiliary agent intoa reaction kettle, introducing carbon dioxide into the reaction kettle, and heating and pressurizing to react, wherein the reaction temperature is 30-80 DEG C, the reaction pressure is 1-6 MPa, and the reaction time is 12-24 hours; separating a liquid and a hydrogen donor from the mixture after the reaction, and acidifying the liquid mixture to obtain a product. The propiolic acid synthesis methoddisclosed by the invention is relatively environment-friendly and low in production cost.
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Paragraph 0020-0029
(2020/07/24)
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- Environment-friendly preparation method of propiolic acid derivatives
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The invention discloses an environment-friendly preparation method of propiolic acid derivatives. The preparation method comprises the following steps: (1) with 2,3-dibromosuccinic acid as a raw material, generating a butynedioic acid salt under alkaline conditions; (2) under an acidic condition, carrying out high-temperature decarboxylation to obtain propiolic acid; and (3) adding corresponding methanol or ethanol into propiolic acid in an extraction solvent, and preparing high-yield propiolate under acidic catalytic conditions under the condition that trimethyl orthoformate or triethyl orthoformate participates in dehydration. In the invention, the propiolic acid preparation method is friendly to environment and high in safety coefficient; and the method provided by the invention can beused for preparing methyl propiolate and ethyl propiolate, and has the advantages of small alcohol consumption, thorough reaction, high yield and easiness in separation.
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Paragraph 0027-0030
(2020/02/14)
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- Synthetic method for flavonoid glycoside drug intermediate propiolic acid
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The invention discloses a synthetic method for the flavonoid glycoside drug intermediate propiolic acid. The synthetic method comprises the following steps: adding 3-aminopropyne and a sodium nitratesolution into a reaction vessel, controlling a stirring speed, controlling the temperature of the obtained solution, carrying out a reaction, adding an ethyl tert-butyl ether solution, raising solution temperature and carrying out a reaction; and adding antimony pentachloride powder and a diglycol diacetate solution, raising solution temperature, carrying out a reaction, then carrying out extraction with the ethyl t-butyl ether solution a plurality of times, carrying out standing for laying of the obtained solution so as to separate an oil layer, washing the oil layer with a potassium chloridesolution a plurality of times, washing the oil layer with a 3-methyl-2-pentanone solution a plurality of times, then washing the oil layer with a dipropylene glycol solution a plurality of times, carrying out recrystallization in a 1,3-dimethylcyclohexane solution and then carrying out dehydration with a dehydrating agent so as to obtain the finished propiolic acid.
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Paragraph 0017-0020; 0022-0024; 0025-0028
(2018/07/30)
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- Gold-catalyzed formal [4π+2π]-cycloadditions of tert-butyl propiolates with aldehydes and ketones to form 4H-1,3-dioxine derivatives
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Gold-catalyzed formal hetero-[4π+2π] cycloadditions of tert-butyl propiolates with carbonyl compounds proceeded efficiently to yield 4H-1,3-dioxine derivatives over a wide scope of substrates. With acetone as a promoter, gold-catalyzed cycloadditions of these propiolate derivatives with enol ethers led to the formation of atypical [4+2]-cycloadducts with skeletal rearrangement.
- Karad, Somnath Narayan,Chung, Wei-Kang,Liu, Rai-Shung
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supporting information
p. 13004 - 13007
(2015/08/06)
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- CuCl catalyzed selective oxidation of primary alcohols to carboxylic acids with tert-butyl hydroperoxide at room temperature
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Direct oxidation of primary alcohols to the corresponding carboxylic acids is performed highly efficiently at room temperature with anhydrous tert-butyl hydroperoxide in the presence of a catalytic amount of easily available CuCl under ligand free conditions in acetonitrile. Benzylic alcohols are more reactive than aliphatic alcohols, and these benzylic alcohols are selectively oxidized to the corresponding acids in the presence of aliphatic alcohols such as 1-octanol and 1-decanol.
- Mannam, Sreedevi,Sekar
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p. 2457 - 2460
(2008/09/20)
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- Process for preparing alkynecarboxylic acids by oxidation of alkyne alcohols
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A process for preparing alkynecarboxylic acids includes the oxidation of an alkyne alcohol with a hypohalite in the presence of a nitroxyl compound at a pH of greater than 7 with continual addition of the alkyne alcohol and of the hypohalite to the reaction mixture.
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- Partial oxidation of alcohols to aldehydes and ketones under mild conditions
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A number of aldehydes and ketones were prepared by partial oxidation of alcohols in air catalyzed by RuO2/ZSM-5 which can be easily prepared with the industrial grade ZSM-5 and RuCl3·xH2O.
- Qian, Guang,Zhao, Rui,Lu, Gaomeng,Qi, Yanxing,Suo, Jishuan
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p. 1753 - 1758
(2007/10/03)
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- Preparation of alkynecarboxylic acids and alkyne alcohol esters of alkynecarboxylic acids by oxidation of alkyne alcohols
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A process for preparing alkynecarboxylic acids and alkyne alcohol esters of alkynecarboxylic acids, includes an oxidation reaction of an alkyne alcohol with from 1 to 10 molar equivalents of a hypohalite based on the number of functional groups to be oxidized in the presence of a nitroxyl compound at a pH of less than 7. There is also a partial oxidation reaction of the alkyne alcohol with from 0.5 to 5 molar equivalents of a hypohalite based on the number of functional groups to be oxidized in the presence of a nitroxyl compound at a pH of less than 7.
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- Permanganate oxidation of unsaturated alcohols in alkaline media
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A study was made on permanganate oxidation of olefinic and acetylenic alcohols in aqueous alkali media. Deprotonation constants of alcohols can be calculated from the kinetic data. The rate constant of alkoxide group oxidation exceeded that of the unsaturated bond. For oxidation of the alcoholic group a mechanism based on hydride ion transfer is proposed.
- Jaky, Miklos,Simon-Trompler, Edit
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p. 561 - 567
(2007/10/03)
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- Spectroscopy of hydrothermal reactions 20: Experimental and DFT computational comparison of decarboxylation of dicarboxylic acids connected by single, double, and triple bonds
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The kinetics and pathways of decarboxylation of aqueous acetylenedicarboxylic acid at pH = 0.97 - 8.02 were studied in situ at 80-160°C and 275 bar by using an FT-IR spectroscopy flow reactor with sapphire windows. The first-order (or pseudo first-order) rate constants and corresponding Arrhenius parameters were obtained for the neutral acid, monoanion, and dianion. The decarboxylation rates are in the order: HO2CC≡CCO2- > HO2CC≡CCO2H > -O2CC≡CCO2-. The decarboxylation mechanisms of these reactants and the propiolic acid product were analyzed by B3LYP/6-31+G(d) density functional theory. The transition state structures were found for the neutral acids and monoanions. In gas phase the transition state structure is a four-member ring involving C-C(O)-O-H. In aqueous solution a cyclic structure incorporating at least one water molecule forms. A comparison of transition state structures for the decarboxylation of β-saturated (succinic) and β-unsaturated (maleic, fumaric, and acetylenedicarboxylic) aliphatic diacids was made with and without incorporating a water molecule. Consistent with experiment, the calculated activation energy for H-atom transfer to the α carbon atom in the decarboxylation step follows the order C≡C C=C C-C.
- Li, Jun,Brill, Thomas B.
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p. 9491 - 9498
(2007/10/03)
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- Sulfuranes Lacking Benzoannelation. Sulfuranes and Other Hypervalent Molecules Studied by 17O-NMR
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The rates of hydrolysis of benzoannelated vs nonbenzoannelated sulfuranes, viz. 5 vs 3 or 5 vs 4, were compared. Benzoannelation was found to provide very modest kinetic stabilization. Crystal structures of sulfuranes 3 and 4 were obtained and compared with each other, with a dibenzoannelated sulfurane, 17, and with a non-sulfurane analogue of 4. Bond length variations could be understood in the context of simple resonance arguments. 17O NMR studies of 3-5 showed that this technique was indeed sensitive to sulfurane structure. For example, the chemical shifts of the two carbonyl oxygens of 4 differed by over 20 ppm. Other hypervalent systems, mainly iodinanes, were studied by 17O NMR. A variety of theoretical methods were surveyed to test how well they could reproduce the geometry of 3. Density functional theory calculation outperformed ab initio geometry optimization at the MP2/3-21G(*) level. Finally, a cis-trans isomerization of the double bond of 11 and one of the two double bonds of 10 was studied.
- Ho, Zwei-Chang,Livant, Peter,Lott, William B.,Webb, Thomas R.
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p. 8226 - 8235
(2007/10/03)
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- Isoxazole-β-carboline derivatives
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β-Carbolines of general Formula I STR1 wherein Y represents the residue STR2 and R a and R b, being identical or different, mean respectively hydrogen, C 1-6 -alkoxy, phenyl, C 3-7 -cyclo-alkyl, optionally substituted C 1-6 -alkyl or C 1-6 -alkoxycarbonyl, and R c and R d, being identical or different, mean respectively hydrogen or C 1-6 -alkyl or jointly a linkage, andR 4 is hydrogen, C 1-6 -alkyl or C 1-6 -alkoxy-C 1-6 -alkyl andR 5 is hydrogen, halogen, OR 6, NR 7 R 8 or CH R 9 R 10 wherein R 6 means C 1-6 -alkyl, C 3-7 -cycloalkyl or an optionally substituted aralkyl, aryl or hetaryl residue, R 7 and R 8, being identical or different, represent hydrogen, C 1-6 -alkyl, C 3-6 -alkenyl, or jointly with the nitrogen atom a saturated heterocyclic five- or six-membered ring which optionally contains a further hetero atom, R 9 means hydrogen or C 1-6 -alkyl, R 10 means hydrogen, C 1-6 -alkyl, OR 11 or NR 12 R 13 wherein R 11 means C 1-6 -alkyl, R 12 and R 13 are identical or different and mean hydrogen, C 1-6 -alkyl or jointly with the nitrogen atom a saturated heterocyclic five- or six-membered ring optionally containing a further hetero atom, are useful to treat epilepsy or anxiety.
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- One-pot Synthesis of α,β-Butenolides from Methyl (Z)-3-Chloroacrylate
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A one-pot synthesis of 4,4-disubstituted α,β-butenolides from methyl (Z)-3-chloroacrylate by successive addition of a Grignard reagent, lithiation, and carbonation is described.
- Barluenga, Jose,Fernandez, Jose R.,Yus, Miguel
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p. 183 - 184
(2007/10/02)
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- RUTHENATE ION CATALYSED OXIDATION OF SOME UNSATURATED ALCOHOLS BY ALKALINE HEXACYANOFERRATE(III) ION
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The kinetics of ruthenate ion catalysed oxidation of allyl alcohol, crotyl alcohol, cinnamyl alcohol and propargyl alcohol by hexacyanoferrate(III) ion in aqueous alkaline media at constant ionic strength indicate no dependence of rate on alkali concentration or ionic strength.The reaction shows first order dependence on ruthenate ion and zero order in hexacyanoferrate(III) ion.The rate of the reaction increases with increase in substrate concentration and shows Michaelis-Menten type of behaviour.The data suggests that the oxidation proceeds via the formation of a complex between an alcohol molecule and ruthenate ion yielding corresponding acids.The reaction has been studied at four different temperatures and thermodynamic parameters have been computed.A plausible mechanism consistent with the experimental results is proposed.
- Dwivedi, R. K.,Verma, Meena,Kumar, Pradeep,Behari, K.
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p. 815 - 818
(2007/10/02)
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- OXIDATION OF ALCOHOLS BY ELECTROCHEMICALLY REGENERATED NICKEL OXIDE HYDROXIDE. SELECTIVE OXIDATION OF HYDROXYSTEROIDS
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Primary alcohols, α,ω-diols and secondary alcohols are easily transformed into carboxylic acids, dicarboxylic acids or ketones, respectively, by heterogeneous oxidation with nickel oxide hydroxide electrochemically regenerated at a nickel hydroxyde electrode.The results are discussed in comparison to those of the nickel peroxide and chromic acid oxidation.The oxidation rate decreases with increasing steric hindrance of the alcohol, thus allowing the selective oxidation of the 3-position in hydroxysteroids.
- Kaulen, Johannes,Schaefer, Hans-J.
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p. 3299 - 3308
(2007/10/02)
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