- A process for the continuous synthesis of β - isophorone
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The invention discloses a continuous synthesis technology of beta-isophorone. The technology comprises the following steps: by using alpha-isophorone as a starting raw material and using molecular sieve as a catalyst, an isomerization reaction is carried out in a column reactor by a reaction-distillation technology, and beta-isophorone is collected at the top of the column reactor; and heavy components are discharged out of the column reactor, and recovery is carried out to obtain alpha-isophorone for recycling. Conditions of the isomerization reaction are as follows: reaction temperature is 180-290 DEG C; reaction pressure is 0.05-0.30 MPa; and the molecular sieve accounts for 0.3-5.0% of mass of alpha-isophorone. In the technology, the molecular sieve and alpha-isophorone are together added into the column reactor to be fully contacted and react, and the obtained beta-isophorone is continuously distilled off. According to the invention, selectivity of products is high; dosage of the molecular sieve catalyst is low; and the catalyst and the heavy components can be conveniently recovered and separated.
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Paragraph 0032-0049
(2017/08/23)
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- Method for preparing beta-isophorone through isomerism of alpha-isophorone
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The invention discloses a method for preparing beta-isophorone through isomerism of alpha-isophorone. The method includes the steps that with a vanadium-containing compound serving as a catalyst and alpha-isophorone serving as a raw material, a liquid phase reaction is carried out, wherein the mass ratio of the raw material to the catalyst is 1000:(1-100); distillation is carried out at the normal pressure and the temperature of 190-240 DEG C, distillate is continuously extracted, and beta-isophorone is constantly transferred out of the reaction system, wherein beta-isophorone accounts for 50%-90% of the weight of the distillate. Compared with a traditional method, the catalyst used in the method is very novel, and the method has the advantages that the use level of the catalyst is low, the reaction speed is high, the reaction conversion rate is high and reaches 90% or above, and the reaction selectivity is good; besides, after the reaction is finished, reactants and reaction by-products can be separated through vacuum distillation.
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Paragraph 0026-0027; 0037; 0043; 0049
(2017/08/25)
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- Method for preparing 3,5,5-trimethyl-3-cyclohexene-1-one
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The invention discloses a method for preparing 3,5,5-trimethyl-3-cyclohexene-1-one. The method comprises the following steps: taking 3,5,5-trimethyl-2-cyclohexene-1-one (alpha-IP) as a raw material, taking preazophosphorine as a catalyst, and carrying out an isomerization reaction by adopting a reactive distillation technique, thereby obtaining the 3,5,5-trimethyl-3-cyclohexene-1-one (beta-IP). The purity of the product beta-IP can reach 99.5-99.8wt%, and the reaction selectivity can reach 99.2-99.9%. The process has the advantages of small catalyst usage amount, high selectivity, avoidance of alkaline separation, less high-boiling residues and the like and a high-efficiency synthetic process.
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Paragraph 0051-0053; 0055; 0056
(2017/10/13)
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- A continuous preparation of 3, 5, 5-trimethyl cyclohexyl-3-ene-1-one
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The invention relates to a method of continuously preparing 3,5,5-trimethyl-3-cyclohexene-1-one (beta-isophorone) by utilization of a heterogeneous catalyst. 3,5,5-trimethyl-2-cyclohexene-1-one is adopted as a raw material, and is subjected to an isomerization reaction by adoption of a reactive distillation column under conditions of a solid alkali catalyst without adding other organic alkalis to obtain the 3,5,5-trimethyl-3-cyclohexene-1-one. The method has advantages of high conversion ratio, good selectivity, less heavy components, easy catalyst recovery, and the like and is a green synthetic process.
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Paragraph 0035-0037
(2017/03/08)
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- Process and apparatus for producing ketoisophorone
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β-isophorone is formed by isomerizing α-isophorone in the presence of an isomerizing catalyst (an aliphatic C5-20 polycarboxylic acid) in an isomerizing-reaction unit 1. The β-isophorone thus formed is oxidized with oxygen in an inert solvent in the presence of an oxidizing catalyst (a complex salt of a transition metal and an N,N'-disalicylidenediamine) in an oxidizing-reaction unit 2, thereby forming ketoisophorone. After removing a low-boiling point component, which is an impurity (non-conjugated cyclic ketone), from the reaction mixture using a distilling unit 3, a high-boiling component (oxidizing catalyst) is separated in a distilling unit 4, and then ketoisophorone is separated from the solvent in the separation unit 5. Thereafter, the solvent containing 0 to 5,000 ppm (weight basis) of the impurities and substantially free from ketoisophorone is recycled to the oxidizing reaction through a recycling line 6. According to the present invention, the combination of the isomerizing reaction and the oxidizing reaction makes it possible to produce ketoisophorone from α-isophorone while maintaining the activity of the oxydizing catalyst.
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Page column 15; 16
(2008/06/13)
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- Ring contraction through epoxide rearrangement: A formal synthesis of capsorubin
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An eight-step synthesis of the cyclopentane keto-alcohol 2, which has previously been converted in one step into the carotenoid pigment capsorubin (1), is described. The key step in our synthesis is a stereospecific epoxide rearrangement with ring contraction, thus producing the cyclopentane ring from an epoxide of a cyclohexene.
- Constantino, Mauricio Gomes,Donate, Paulo Marcos,Frederico, Daniel,Carvalho, Tecia Vieira,Cardoso, Luiz Eduardo,Zukerman-Schpector, Julio
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p. 3327 - 3340
(2007/10/03)
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- Selective Epoxidation of α-Isophorone with Mesoporous Titania-Silica Aerogels and tert-Butyl Hydroperoxide
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Amorphous, mesoporous TiO2-SiO2 mixed oxides, synthesised using a sol-gel process followed by extraction with supercritical CO2, show high selectivities (98percent) in the heterogeneous epoxidation of α-isophorone in ethylbenzene at 60 deg C.
- Hutter, R.,Mallat, T.,Baiker, A.
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p. 2487 - 2488
(2007/10/03)
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- STEREOCHIMIE-LII. CONTROLE ORBITALAIRE DE LA STEREOCHIMIE DES REACTIONS-III EFFETS DES GROUPES β-FLUORO ET β-CYANO SUR LA STEREOCHIMIE ET LA CINETIQUE DE LA REDUCTION DE CYCLOHEXANONES PAR LE TRITERTIOBUTOXYALUMINOHYDRURE DE LITHIUM
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The respective influences of β-fluoro and β-cyano groups on the reduction of ketones by Li(t-BuO)3AlH on the stereoselectivities of the reduction with and without added cryptands, and with and without added alkyl fluoride and nitrile, were compared with ab initio calculations using the frontier orbitals of analogous carbonyl compounds to give energy values
- Agami, C.,Kazakos, A.,Levisalles, J.,Sevin, A.
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p. 2977 - 2981
(2007/10/02)
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