- DIELS- ALDER RING-OPENING PROCESS
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The invention is directed to a process for the ring-opening of a cycloadduct of formula I obtainable from a reaction of a furanic compound and a diene, said process comprising contacting the cycloadduct with an acidic mixture comprising sulfuric acid and an activating agent to obtain a ring-opened product. The present invention is particularly directed a continuous process.
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Page/Page column 27
(2019/11/19)
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- Renewable production of phthalic anhydride from biomass-derived furan and maleic anhydride
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A route to renewable phthalic anhydride (2-benzofuran-1,3-dione) from biomass-derived furan and maleic anhydride (furan-2,5-dione) is investigated. Furan and maleic anhydride were converted to phthalic anhydride in two reaction steps: Diels-Alder cycloaddition followed by dehydration. Excellent yields for the Diels-Alder reaction between furan and maleic-anhydride were obtained at room temperature and solvent-free conditions (SFC) yielding 96% exo-4,10-dioxa-tricyclo[5.2.1.0]dec-8-ene-3,5-dione (oxanorbornene dicarboxylic anhydride) after 4 h of reaction. It is shown that this reaction is resistant to thermal runaway because of its reversibility and exothermicity. The dehydration of the oxanorbornene was investigated using mixed-sulfonic carboxylic anhydrides in methanesulfonic acid (MSA). An 80% selectivity to phthalic anhydride (87% selectivity to phthalic anhydride and phthalic acid) was obtained after running the reaction for 2 h at 298 K to form a stable intermediate followed by 4 h at 353 K to drive the reaction to completion. The structure of the intermediate was determined. This result is much better than the 11% selectivity obtained in neat MSA using similar reaction conditions.
- Mahmoud, Eyas,Watson, Donald A.,Lobo, Raul F.
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p. 167 - 175
(2014/01/06)
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- Inclusion complex containing epoxy resin composition for semiconductor encapsulation
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The invention is an epoxy resin composition for sealing a semiconductor, including (A) an epoxy resin and (B) a clathrate complex. The clathrate complex is one of (b1) an aromatic carboxylic acid compound, and (b2) at least one imidazole compound represented by formula (II): wherein R2 represents a hydrogen atom, C1-C10 alkyl group, phenyl group, benzyl group or cyanoethyl group, and R3 to R5 represent a hydrogen atom, nitro group, halogen atom, C1-C20 alkyl group, phenyl group, benzyl group, hydroxymethyl group or C1-C20 acyl group. The composition has improved storage stability, retains flowability when sealing, and achieves an effective curing rate applicable for sealing delicate semiconductors.
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- Metallo-β-lactamase inhibitory activity of phthalic acid derivatives
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4-Butyl-3-methylphthalic acid was recognized as a metallo-β-lactamase inhibitor. The structure-activity relationship study of substituted phthalic acids afforded 3-phenylphthalic acid derivatives as potent IMP-1 inhibitors. On the other hand, 3-substituted with 4-hydroxyphenyl phthalic acid derivative displayed a potent combination effect with biapenem (BIPM) against Pseudomonas aeruginosa that produce IMP-1.
- Hiraiwa, Yukiko,Morinaka, Akihiro,Fukushima, Takayoshi,Kudo, Toshiaki
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scheme or table
p. 5162 - 5165
(2010/03/24)
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- Synthesis of 1,2- and 1,3-dicarboxylic acids via Pd(II)-catalyzed carboxylation of aryl and vinyl C-H bonds
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A Pd(II)-catalyzed reaction protocol for the direct carboxylation of benzoic and phenylacetic acid derivatives to form dicarboxylic acids has been developed. The reaction conditions are also applicable for the carboxylation of vinyl C-H bonds. The first C-H insertion Pd-aryl complex from carboxylic acids has been characterized by X-ray crystallography. Copyright
- Giri, Ramesh,Yu, Jin-Quan
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supporting information; experimental part
p. 14082 - 14083
(2009/03/11)
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- Structural elucidation of an oxidation product of sedimentary porphyrins by one-pot synthesis of 3-methylphthalimide
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One-pot synthesis of 3-methylphthalimide was achieved from 1,2,3-trimethylbenzene. The starting compound was oxidized in two steps to produce methylphthalic acids. The o-isomer was converted into its anhydride, which was subjected to thermal reaction with urea to form 3-methylphthalimide. The product was identical with the reported oxidation product of sedimentary porphyrins.
- Nomoto,Kozono,Mita,Shimoyama
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p. 1975 - 1976
(2007/10/03)
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