- Kinetics and mechanism of the alkaline hydrolysis of maleimide
-
The kinetics of hydrolysis of maleimide was carried out within the [OH-] range of 2.46 x 10-6 to 2.0 M at 30°C. The observed pseudo-first-order rate constants, k(obs), follow the empirical equation: k(obs) = (A1[OH-] + A2[OH-]2)/(1 + A3[OH-]). Both ionized and un-ionized forms of maleimide have been suggested to be involved in hydrolysis. The nucleophilic attacks by hydroxide ion at the carbonyl carbon of both ionized and un-ionized maleimide and by water at the carbonyl carbon of ionized maleimide to form tetrahedral intermediates are considered to be the rate-determining steps. The observed results obtained at different 1,4-dioxane-water compositions have revealed an increase in k(obs) with a decrease in 1,4-dioxane content which could be attributed to the higher polarity of the transition state compared with the reactant state.
- Khan
-
-
Read Online
- Three-Component Synthesis of Quinolines Based on Radical Cascade Visible-Light Photoredox Catalysis
-
Synthesis of highly substituted quinolines has been developed based on three-component radical cascade based on visible-light photoredox catalysis. This tandem coupling reaction has been coordinated to proceed with high chemoselectivity based on the differential electronic properties of coupling partners. Subjection of electron-rich β-aminoacrylates with electron-deficient halides and alkenes to the optimized conditions leads to the formation of quinolines in good yields after in situ oxidation of tetrahydroquinolines. Detailed mechanistic studies which reveal an unexpected reaction pathway is described. (Figure presented.).
- Choi, Jun-Ho,Park, Cheol-Min
-
supporting information
p. 3553 - 3562
(2018/09/22)
-
- PROCESS FOR PRODUCING MALEIMIDE
-
PROBLEM TO BE SOLVED: To provide a process for imidization at low temperature without using a strongly acidic dehydration catalyst, in producing maleimide from maleamic acid using an acid catalyst. SOLUTION: In a process for producing maleimide, when imidizing a maleamic acid obtained by reacting a primary amine and a maleic anhydride, in a solvent using a dehydration catalyst, an aliphatic carboxylic acid and/or aliphatic anhydride is used as the dehydration catalyst. The use amount of the aliphatic carboxylic acid and/or aliphatic anhydride is 0.1 equivalent or more in total of the aliphatic carboxylic acid and aliphatic anhydride with respect to the primary amine. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2017,JPOandINPIT
- -
-
Paragraph 0019; 0021; 0024-0026
(2017/10/25)
-
- METHODS FOR PRODUCING POLYASPARTIC ACID PRECURSOR POLYMER AND POLYASPARTIC ACID SALT
-
Disclosed are a method for producing a polyaspartic acid precursor polymer by polymerization using at least one kind selected from a product obtained from maleic anhydride and ammonia and, maleamic acid as a monomer, wherein at least part of carboxyl groups in the monomers are a tertiary amine salt; and an industrially inexpensive and simple method for producing a polyaspartic acid salt by treating the polyaspartic acid precursor polymer obtained by this method with a basic aqueous solution.
- -
-
-
- Synthesis of N-formylmaleamic acid and some related N-formylamides
-
Two syntheses of N-formylmaleamic acid and some related N-formylamides are described which take place under very mild conditions.
- Behrman, Edward J.,Hillenbrand, Edward L.
-
experimental part
p. 170 - 172
(2009/04/16)
-
- Nucleic acid triggered catalytic drug and probe release
-
The present invention provides methods and combinations of compositions for the modulation of diseases caused by a subject possessing a disease-specific nucleic acid sequence. Included are methods for the treatment, prevention and/or inhibition of the diseases by administering a combination of a prodrug component, drug and catalytic component such that the drug is catalytically released when contacting the combination to the disease-specific nucleic acid sequence.
- -
-
-
- Ethylenically unsaturated imidazidolidinone monomers
-
Classes of urea functional compounds and compositions containing the same are disclosed which are particularly suitable for use as a wet adhesion promoters in coatings, especially in aqueous emulsion systems used to make latex paints. Compositions containing the same, as well as additional uses thereof are also disclosed.
- -
-
-
- Compounds containing a michael-acceptor, especially maleimide or maleic acid derivatives, directly or indirectly linked to a chromophore and their use in long lasting sunscreen compositions
-
The present invention relates to compounds which are useful as sunscreens. The compounds persist on the skin for much longer than conventional sunscreens because they comprise a Michael acceptor linked directly or indirectly to a chromophore. The Michael acceptor is capable of undergoing a conjugate addition reaction with thiol groups present in cysteine residues of keratin and thus the compound is chemically bound to the skin and will not be removed by immersion in water.
- -
-
-
- COMPOUNDS AND COMPOSITIONS FOR INHIBITION OF CYCLOOXYGENASE ACTIVITY
-
The present invention includes N-substituted maleimides (1(H)-Pyrrole-2,5-dione (Maleimide) analogs and succinimides which act as potent nonsteroidal anti-inflammatory drugs and are capable of dual inactivation or selective inactivation of the cyclooxygenase and the peroxidase activities of prostaglandin endoperoxide synthase (PGHS).
- -
-
-
- Long chain carboxylic acid maleimides
-
Provided are novel superoxide dismutase derivatives represented by the following general formula (I) STR1 wherein [SOD] is a superoxide dismutase residue derived by removal of two mercapto groups, and W is a divalent long chain hydrocarbon residue which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom and a group of -N(R)- (R being a lower alkyl group). The SOD derivatives retain most of the enzymatic activities of unmodified SOD and have much longer plasma half-life than unmodified SOD. They are effective for treating various diseases caused by active oxygen species. Also provided are chemical modifiers to prepare the above SOD derivatives.
- -
-
-
- Superoxide dismutase derivatives
-
Provided are novel superoxide dismutase derivatives represented by the following general formula (I) wherein [SOD] is a superoxide dismutase residue derived by removal of two mercapto groups, and W is a divalent long chain hydrocarbon residue which may optionally be interrupted by one or more groups each independently selected from the group consisting of an oxygen atom, a sulfur atom and a group of -N(R)- (R being a lower alkyl group). The SOD derivatives retain most of the enzymatic activities of unmodified SOD and have much longer plasma half-life than unmodified SOD. They are effective for treating various diseases caused by active oxygen species. Also provided are chemical modifiers to prepare the above SOD derivatives.
- -
-
-
- Ethylenically unsaturated compounds containing 1-hydrocarbyloxy-2,2,6,6-tetramethylpiperidine moieties, and polymers, copolymers and stabilized compositions
-
Ethylenically unsaturated compounds containing 1-hydroxycarbyloxy-2,2,6,6-tetramethylpiperidine moieties represent reactable stabilizers which may be homopolymerized or copolymerized with other ethylenically saturated monomers to form non-migrating, light stabilizers which are very effective in stabilizing polyolefins and other polymer substrates against the deleterious effects of actinic light.
- -
-
-
- CYCLIC HYDROCARBONS WITH AN AMINOALKYL SIDECHAIN
-
Provided are cyclic hydrocarbons of Formula I with an aminoalkyl sidechain that are useful for treating phospholipase A2 mediated conditions, diabetes, and obesity.
- -
-
-
- Process for the preparation of N-maleoyl activated esters of amino acids
-
A process for the preparation of activated esters of certain N-maleoyl amino acids is disclosed. In the process, maleamic acids are cyclized and esterified to the desired products by the initial reaction with an acid halide reagent followed by a subsequent reaction with the appropriate hydroxyl-containing compound. The activated esters of N-maleoyl amino acids are particularly suited for linking compounds containing an amino group with those containing a thiol group.
- -
-
-
- Isomaleimide and isophthalimide derivatives of chromophors
-
Novel Isomaleimido and isophthalimido derivatives of chromophoric compounds are provided which are useful in analytic techniques for the detection and measurement of biological compounds such as bacteria, enzymes, hormones and the like.
- -
-
-
- Isomaleimide and isophthalamide derivatives of chromophors
-
Novel isomaleimido and isophthalimido derivatives of chromophoric compounds are provided which are useful in analytical techniques for the detection and measurement of biological compounds such as bacteria, enzymes, hormones and the like.
- -
-
-
- Bismaleimide compounds
-
Bismaleimides of the formula STR1 wherein R1 and R2 each independently is H, C1-4 -alkyl, C1-4 -alkoxy, C1 or Br, or R1 and R2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R1 and R2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the alkylene bridging group, optionally, is substituted by 1-3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.
- -
-
-
- Maleimido substituted aromatic cyclotriphosphazenes
-
4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.
- -
-
-
- Resolution enhancing maleimide spin label for biological EPR studies
-
An improved maleimide spin label, namely, N-(15 N-oxyl-2,2,6,6-tetra-methyl-4-piperidinyl-d17) maleimide is provided for EPR spectroscopic investigations of biomedically relevant problems. Isotopic substitution of nitrogen-15 in the N--O bond and deuterium in the methyl groups (-CD3) and in all positions of the piperidine ring results in simplification of the EPR spectrum, greatly improved resolution, and a marked increase in signal intensity.
- -
-
-
- Opening of the Furan Ring in 5-Azido-2-furaldehyde
-
Fission of the furan ring in 5-azido-2-furaldehyde is described. α-Furylnitrene, formed from α-azido furan derivatives, is stabilized by the furan ring fission.Transformation of the intermediate to quinoxaline and pyrazole derivatives is also studied.
- Povazanec, Frantisek,Kovac, Jaroslav,Hesek, Dusan
-
p. 150 - 154
(2007/10/02)
-
