941-69-5Relevant articles and documents
Dual organic dyes as a pseudo-redox mediation system to promotion of tandem oxidation /[3+2] cycloaddition reactions under visible light
Koohgard, Mehdi,Hosseinpour, Zeinab,Hosseini-Sarvari, Mona
, (2021/05/10)
An atom- and step-economy protocol has been developed to synthesize some new biologically active pyrrolo[2,1-a]isoquinoline alkaloids via redox mediation system under visible light irradiation. A vast variety of double and triple bonds, as dipolarophiles, treated with in situ generated azomethine ylides to prepare corresponding products in good to excellent yields. This metal-free method effectively promoted oxidation/[3 + 2] cycloaddition/oxidative/aromatization domino reaction without further oxidant using dual organic dyes as pseudo-redox mediation system. Besides, for most of the products, product precipitate was readily separated from reaction media. To the best of our knowledge, this is the first report of dual dyes as a pseudo-redox mediation system.
Room-Temperature Synthesis of Isoindolone Spirosuccinimides: Merger of Visible-Light Photocatalysis and Cobalt-Catalyzed C-H Activation
Sen, Chiranjit,Sarvaiya, Bhavesh,Sarkar, Souvik,Ghosh, Subhash Chandra
, p. 15287 - 15304 (2020/12/02)
A room-temperature C-H bond functionalization of benzamides has been developed by merging a photocatalyst with a cobalt catalyst for the synthesis of isoindolone spirosuccinimides. The reaction proceeds in aerobic conditions and does not require any sacrificial external oxidants such as Ag(I) or Mn(III) salts. Visible light activates the photocatalyst, and it acts as an electron-transfer reagent and helps in the fundamental organometallic steps by modulating the oxidation state of the cobalt complex. This C-H bond functionalization and spirocyclization showed wide substrate scope and good functional group tolerance. A possible reaction mechanism was proposed from the experimental outcome, showing that C-H bond activation is irreversible and not the rate-determining step.
Application of maleimide compound as chitin synthase inhibitor
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Paragraph 0024-0027, (2020/07/12)
The invention discloses an application of a maleimide compound as shown in a formula I. In the formula I, R0 is phenyl, benzyl, phenethyl, phenylpropyl, p-fluorophenyl, p-chlorophenyl, p-bromophenyl,p-methoxyphenyl, p-methylphenyl or p-hydroxyphenyl, R1 is hydrogen, methyl, phenyl or chlorine; and R2 is hydrogen, methyl, phenyl or chlorine. The provided maleimide compound has a good inhibition effect on chitin synthase.
Regioselective hydroarylation and arylation of maleimides with indazoles: Via a Rh(iii)-catalyzed C-H activation
Ghosh, Asim Kumar,Samanta, Sadhanendu,Ghosh, Payel,Neogi, Sukanya,Hajra, Alakananda
supporting information, p. 3093 - 3097 (2020/05/08)
Switchable Rh(iii)-catalyzed highly regioselective hydroarylation and oxidative arylation of maleimides with 2-arylindazoles via C-H activation have been demonstrated. The reaction affords 3-(2-(2H-indazol-2-yl)phenyl)succinimide and 3-(2-(2H-indazol-2-yl)phenyl)maleimide derivatives in high yields with wide functional group tolerance. A mechanistic study was performed to depict C-H bond cleavage that might be involved in the turnover limiting step.
Visible-Light-Mediated Dearomatisation of Indoles and Pyrroles to Pharmaceuticals and Pesticides
Schilling, Waldemar,Zhang, Yu,Riemer, Daniel,Das, Shoubhik
supporting information, p. 390 - 395 (2019/12/15)
Dearomatisation of indole derivatives to the corresponding isatin derivatives has been achieved with the aid of visible light and oxygen. It should be noted that isatin derivatives are highly important for the synthesis of pharmaceuticals and bioactive compounds. Notably, this chemistry works excellently with N-protected and protection-free indoles. Additionally, this methodology can also be applied to dearomatise pyrrole derivatives to generate cyclic imides in a single step. Later this methodology was applied for the synthesis of four pharmaceuticals and a pesticide called dianthalexin B. Detailed mechanistic studies revealed the actual role of oxygen and photocatalyst.
Method for synthesizing N-phenylmaleimide through one-step method
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Paragraph 0031-0036, (2019/05/08)
The invention provided a method for synthesizing N-phenylmaleimide through a one-step method. Under the situation of not adding a polymerization inhibitor, the N-phenylmaleimide is directly synthesized by aniline and maleic anhydride through the one-step method. The method comprises the steps that a benzene solvent and a catalyst are added into a rector, maleic anhydride and a cosolvent are addedat the temperature of 50-100 DEG C, temperature increasing and reflux are conducted, then the aniline is added dropwise until the aniline is completed dropped, the time is maintained for 25-100 min, N-phenylmaleimide reaction liquid is obtained, and the yield of the reaction liquid is 98.5% or above; and the reaction liquid is washed, neutralized and distilled, and thus a product is obtained. According to the method, the time is saved, energy consumption is low, the cost is low, the working procedures are less, the content is high (can reach 99.2% or above), operation is easy, the environment-friendly effect is achieved, and the method is an improved version of a process for synthesizing N-phenylmaleimide through the one-step method.
SYNTHESIS METHOD OF N-SUBSTITUTED MALEIMIDE USING SOLID ACID CATALYSTS
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Paragraph 0070-0074, (2019/06/07)
The present invention relates to a synthesis method of N-substituted maleimides using a non-homogeneous solid acid catalyst, and particularly, a synthesis method of N-substituted maleimides with high synthesis yield by using a zirconium(IV) hydrogen phosphate as a catalyst, by which, the loss of the catalyst is minimized, the separation and recovering processes of the catalyst are simplified, in case when the activity of the separated and recovered catalyst is decreased, the complete regeneration of the catalyst is possible via washing or firing, and solvents that could be used during a washing process of the catalyst are not limited.
METHOD FOR PURIFYING N-SUBSTITUTED MALEIMIDE
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Paragraph 0113-0138, (2019/10/11)
The present invention relates to a method for purifying N-substituted maleimide comprising steps of: 1) preparing an N-substituted maleimide solution produced by conducting a reaction of maleic anhydride and primary amine in the presence of an organic solvent and a catalyst; and 2) cooling the N-substituted maleimide solution to 50 to 70anddeg;C to separate crystallized N-substituted maleimide, wherein the organic solvent is an alkane-based solvent having 9 or more carbon atoms. The method for purifying N-substituted maleimide of the present invention has an effect of being purified with high-purity N-substituted maleimide without performing a distillation process.(AA) Squalane(PMI solubility Wt.%)(BB) Temperature ( anddeg;C )COPYRIGHT KIPO 2019
METHOD FOR PREPARING IMIDE COMPOUNDS
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Paragraph 0149-0156, (2019/10/19)
The present invention relates to a method for recycling a catalyst cleaning solvent for manufacturing N-substituted maleimide and a method for manufacturing N-substituted maleimide using the same. Specifically, by a step of washing a catalyst recovered by a catalyst recovery process for manufacturing N-substituted maleimide through a washing solvent; and a step of regeneration which is adding a maleic acid isomerization catalyst to the washing solvent after washing to isomerize maleic anhydride or maleic acid included in the washing solvent into fumaric acid, and then removing and distilling the same, it is possible to regenerate and recycle the catalyst cleaning solvent for manufacturing N-substituted maleimide, thereby being able to increase economic efficiency and productivity.COPYRIGHT KIPO 2019
METHOD FOR PREPARING IMIDE COMPOUNDS
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Paragraph 0118-0121, (2019/10/29)
The present invention relates to a method for recycling N-substituted maleimide washing water and a method for manufacturing N-substituted maleimide using the same. Specifically, by adding and isomerizing a catalyst capable of isomerizing maleic anhydride or maleic acid present in the N-substituted maleimide washing waste water with fumaric acid, the washing waste water is regenerated and recycled, thereby being able to reduce additional wastewater treatment facilities and costs for maintaining the same unlike in the prior art.COPYRIGHT KIPO 2019
