- Hydrogenolysis of Amide Acetals and Iminium Esters
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Amide acetals and iminium esters were hydrogenated into amines under very mild reaction conditions over common hydrogenation catalysts. This finding provides a new strategy for the selective reduction of amides. The synthetic utility of this approach was demonstrated by the selective reduction of amides bearing ester and nitrile groups.
- Kadyrov, Renat
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- Synthesis and Antibacterial Activity of Polymerizable Acryloyloxyalkyltriethyl Ammonium Salts
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This study reports an efficient and practical synthetic approach for the synthesis of a particularly important class of polymerizable quaternary ammonium salts (PQASs), that is, acryloxyalkyltriethylammonium bromides (AATEABs), which may find application as antimicrobial coatings for commercial membranes with antifouling and anti-biofouling properties, to be used for wastewater treatment. The synthetic method is based on a simple two-step procedure from commercially available substrates, entirely carried out under air and without any need for chromatographic purification. All the newly synthesized AATEABs were tested for their antimicrobial activity, and the results showed that AATEABs bearing an alkyl chain of 11 and particularly 12 carbon atoms possessed significant activity against Gram positive bacteria and yeast strains.
- Mancuso, Raffaella,Amuso, Roberta,Armentano, Biagio,Grasso, Giuseppe,Rago, Vittoria,Cappello, Anna Rita,Galiano, Francesco,Figoli, Alberto,De Luca, Giorgio,Hoinkis, Jan,Gabriele, Bartolo
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- Homogeneously Catalyzed Synthesis of β-Amino Alcohols ans Vicinal Diamines from Ethylene Glycol and 1,2-Propanediol
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Disubstituted β-amino alcohols and tetrasubstituted vicinal alkanediamines have been synthesized in high yield and at mild temperatures by the selective amination of ethylene glycol and 1,2-propanediol catalyzed by ruthenium or iridium complexes.
- Marsella, John A.
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- Kinetics of hydrolysis of procaine in aqueous and micellar media
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The kinetics of alkaline hydrolysis of procaine under the pseudo-first-order condition ([OH-] a [procaine]) has been carried out. N,N-Diethylaminoethanol and p-aminobenzoate anion were obtained as the hydrolysis product. The rate of hydrolysis was found to be linearly dependent upon [NaOH]. The addition of cationic cetyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DDTAB) and tetradecyltrimethylammonium bromide, and anionic sodium dodecyl sulfate (SDS) micelles inhibited the rate of hydrolysis. The maximum inhibitive effect on the reaction rate was observed for SDS micelles, whereas among the cationic surfactants, CTAB inhibited most. The variation in the rate of hydrolysis of procaine in the micellar media is attributed to the orientation of a reactive molecule to the surfactant and the binding constant of procaine with micelles. The rate of hydrolysis of procaine is negligible in DDTAB micelles. The observed results in the presence of cationic micelles were treated on the basis of the pseudophase ion exchange model. The results obtained in the presence of anionic micelles were treated by the pseudophase model, and the various kinetic parameters were determined.
- Al-Blewi, Fawzia Faleh,Al-Lohedan, Hamad A.,Rafiquee,Issa, Zuheir A.
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- Inclusion complexation of novocaine by β-cyclodextrin in aqueous solutions
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The formation of inclusion complexes between β-cyclodextrin (β-CD) and the local anesthetic 2-(diethylamino)ethyl-p-amino-benzoate (novocaine) in aqueous solutions under different acidity conditions, using steady-state fluorescence or UV-vis spectroscopie
- Iglesias, Emilia
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- A method for preparing alkyl amine
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The invention discloses a preparation method for alkyl alcohol amine. The preparation method comprises the following steps: (1) feeding alkyl amine and a reaction promoter alkanolamine into a reaction kettle for stirring and mixing; (2) adding epoxy alkane for synthesis, wherein the feeding molar ratio of epoxy alkane for synthesis to alkyl amine is higher than the theoretical reaction molar ratio; (3) after the feeding is finished, carrying out heating and pressurization; (4) carrying out heat preservation conversion rate to obtain a crude product; (5) conducting continuous distillation on the crude product to separate out alkyl alcohol amine. During the preparation, alkanolamine is primary alkanolamine or secondary alkanolamine. Compared with the prior art, the preparation method provided by the invention adopts the technical scheme that alkanolamine is taken as the reaction promoter instead of water as a catalyst, so that the conversion rate of alkyl amine can reach 99.0% in general, the highest conversion rate can reach 99.9%, and the highest recovery rate of alkyl alcohol amine can reach 99.8%. Therefore, the preparation method provided by the invention has the advantages of being high in raw material conversion rate and recovery rate.
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Paragraph 0102-0105
(2017/07/12)
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- Design, Synthesis, and Biological Evaluation of Scutellarein Derivatives Based on Scutellarin Metabolic Mechanism in Vivo
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Three series of scutellarein derivatives have been designed and synthesized based on metabolic mechanism of scutellarin (1) in vivo. Their thrombin inhibition activities were tested through the analyzation of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and fibrinogen (FIB). The antioxidant activities of these target products were assessed by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay and the ability to protect PC12 cells against H2O2-induced cytotoxicity, and their solubilities were evaluated by ultraviolet (UV) spectrophotometer. The results showed that the two isopropyl groups substituted derivative (18c) demonstrated stronger anticoagulant activity, better water solubility, and good antioxidant activity compared with scutellarein (2), which warrants further development of 18c as a promising agent for ischemic cerebrovascular disease treatment. Three series of scutellarein derivatives have been designed and synthesized based on metabolic mechanism of scutellarin (1) in vivo. The results of the biological evaluation showed that the two isopropyl groups substituted derivative (18c) demonstrated stronger anticoagulant activity, better water solubility, and good antioxidant activity compared with scutellarein (2), which warrants further development of 18c as a promising agent for ischemic cerebrovascular disease treatment.
- Dong, Ze-Xi,Shi, Zhi-Hao,Li, Nian-Guang,Zhang, Wei,Gu, Ting,Zhang, Peng-Xuan,Wu, Wen-Yu,Tang, Yu-Ping,Fang, Fang,Xue, Xin,Li, He-Min,Cheng, Hai-Bo,Yang, Jian-Ping,Duan, Jin-Ao
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p. 946 - 957
(2016/05/24)
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- Platinum-Catalyzed, Terminal-Selective C(sp3)-H Oxidation of Aliphatic Amines
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This Communication describes the terminal-selective, Pt-catalyzed C(sp3)-H oxidation of aliphatic amines without the requirement for directing groups. CuCl2 is employed as a stoichiometric oxidant, and the reactions proceed in high yield at Pt loadings as low as 1 mol%. These transformations are conducted in the presence of sulfuric acid, which reacts with the amine substrates in situ to form ammonium salts. We propose that protonation of the amine serves at least three important roles: (i) it renders the substrates soluble in the aqueous reaction medium; (ii) it limits binding of the amine nitrogen to Pt or Cu; and (iii) it electronically deactivates the C-H bonds proximal to the nitrogen center. We demonstrate that this strategy is effective for the terminal-selective C(sp3)-H oxidation of a variety of primary, secondary, and tertiary amines.
- Lee, Melissa,Sanford, Melanie S.
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supporting information
p. 12796 - 12799
(2015/10/28)
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- Synthesis of scutellarein derivatives to increase biological activity and water solubility
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In order to improve the biological activity and water solubility of scutellarin (1), some derivatives of its main metabolite (scutellarein) were designed and synthesized. All the compounds were tested for their thrombin inhibition activity through the analyzation of thrombin time (TT), activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen (FIB). Their antioxidant activities were assessed by measuring their scavenging capacities toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ability to protect PC12 cells against H2O2-induced cytotoxicity, their water solubility were also assessed by ultraviolet (UV) spectrophotometer. The results showed that compound 8b demonstrated stronger anticoagulant and antioxidant activity, better water solubility compared with scutellarein (2), which warrants it as a promising agent for the treatment of ischemic cerebrovascular disease.
- Shi, Zhi-Hao,Li, Nian-Guang,Shi, Qian-Ping,Zhang, Wei,Dong, Ze-Xi,Tang, Yu-Ping,Zhang, Peng-Xuan,Gu, Ting,Wu, Wen-Yu,Fang, Fang,Xin-Xue,Li, He-Min,Yang, Jian-Ping,Duan, Jin-Ao
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p. 6875 - 6884
(2015/11/11)
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- Process for producing alkanolamines
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A process for producing an alkanolamine includes supplying a reactive distillation apparatus having an inner contacting surface which simultaneously facilitates a reaction process and a distillation process, feeding a first reactant including an amine represented by R′3-XNHX, wherein R′ is a hydrocarbon group, and X is 1, 2, or 3, feeding a second reactant including an akylene oxide represented by R″O, wherein R″ is a C2-C10-alkylene, feeding a catalyst in an amount from 0% to about 15% by weight of a mixture of the first reactant, the second reactant and the catalyst; recycling an overhead output from an overhead portion including an unreacted portion of the amine and the catalyst to achieve a substantially total reflux of the amine and the catalyst, and collecting a product output including an alkanolamine, the alkanolamine being a member selected from the group consisting of a monoalkanolamine, a dialkanolamine, and a trialkanolamine.
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- Hydrolytic profile for ester- or amide-linkage by carboxylesterases pI 5.3 and 4.5 from human liver
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Carboxylesterases (EC 3.1.1.1) from human liver were purified using Q- Sepharose, Sephadex G-150, isoelectrofocusing and Con A-Sepharose. The calculated molecular mass of the pI 5.3 enzyme was 120 kDa and 61 kDa from the results of Sephadex G-150 gel filtration and SDS-polyacrylamide gel electrophoresis (PAGE), respectively, suggesting that this enzyme is a dimer. On the other hand, carboxylesterase pI 4.5, with a molecular-mass of 64 kDa, was a monomer. The activities of both enzymes were inhibited by typical serine enzyme inhibitors. Amino acid sequence analysis of the purified enzymes pI 5.3 and 4.5 showed high homology with rabbit carboxylesterase form 1 and 2, respectively. The results also suggested that carboxylesterase pI 5.3 is identical to the deduced amino acid sequence from cDNA for HUI, and that carboxylesterase pI 4.5 is identical to the deduced amino acid sequence from the cDNA registered as human carboxylesterase (hCE-2) in GenBank. We first purified carboxylesterase pI 4.5 and investigated its hydrolytic activity upon various drugs. The two enzymes differed in substrate specificity. Prodrugs of angiotensin-converting enzyme inhibitors, such as delapril and imidapril, were converted to active metabolites by carboxylesterase pI 5.3, but not by carboxylesterase pI 4.5. The hydrolysis velocity of temocapril by carboxylesterase pI 5.3 was 12-fold faster than by carboxylesterase pI 4.5. In contrast, aspirin oxybutynin and procaine were hydrolyzed by only carboxylesterase pI 4.5. We also found that an amide- linkage in drugs, except for that in aniracetam was not a good substrate for the two enzymes. Consequently, carboxylesterases pI 5.3 and 4.5 maybe involved in the metabolism of various drugs containing an ester-linkage.
- Takai, Satomi,Matsuda, Ayuka,Usami, Yoshiko,Adachi, Tetsuo,Sugiyama, Tadashi,Katagiri, Yoshihiro,Tatematsu, Masae,Hirano, Kazuyuki
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p. 869 - 873
(2007/10/03)
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- Nucleophilicity towards a Vinylic Carbon Atom: Rate Constants for the Addition of Amines to the 1-Methyl-4-vinylpyridinium Cation in Aqueous Solution
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Second-order rate constants (kNu) have been measured for the addition of 44 primary amines (including five α-effect amines), 28 secondary amines, 19 tertiary amines, ammonia and hydroxide ion to the vinyl group of the 1-methyl-4-vinylpyridinium cation (1) in aqueous solution at 25 deg C (ionic strength 0.1 mol dm-3).Nucleophilic attack is shown to be rate-determining for primary and secondary amines being generally more reactive than primary amines, with secondary amines of the same basicity.After classification of these species in terms of structure, they describe a number of Broensted-type correlations having βnuc in the range 0.35-0.54 for six structural classes of primary amine, βnuc = 0.48 for α-effect amines, and βnuc in the range 0.23-0.34 for four structural classes of secondary amine.Substitution upon the α-carbon atom reduces amine nucleophilicity of both primary and secondary amines.The presence of an unsaturated carbon atom (either sp2- or sp-hybridized) as the β-carbon atom leads to an enhanced reactivity relative to the corresponding β-sp3 species in all cases.Tertiary amines are in general less reactive than other amines of the same basicity.Broensted-type plots for tertiary amines present the appearance of random scatter which is not readily decipherable in terms of structure. β-Hydroxy and β-amino tertiary amines are unusually reactive relative to their basicity.All of these phenomena suggest that protonation of the carbanionic intermediate by a molecule of water is the rate-determining step for the addition of tertiary amines to 1.Rate constants for the attack of primary and secondary amines on 1 are shown to correlate with literature data for a variety of other reactions involving rate-determining nucleophilic attack of amines upon electrophilic carbon.These kNu for primary and secondary amines reacting with 1 are also shown to correlate with Ritchie's N+ parameters for nucleophilic attack at electrophilic sp2-carbon.N+ parameters for amine nucleophiles have not been widely available previously; the parameters that have been available for selected amines are known to be sensitive to the nature of the defining electrophile.The minimal steric hindrance at the electrophilic centre in nucleophilic attack upon 1 suggests that this species is an appropriate electrophile for the definition of N+ parameters for amine nucleophiles; these parameters are evaluated for 70 primary and secondary amines and ammonia and are suggested to provide an appropriate data base for future investigations of the reactivity and selectivity of amine attack upon sp2-carbon electrophiles in aqueous solution.
- Heo, Christina K. M.,Bunting, John W.
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p. 2279 - 2290
(2007/10/02)
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- Processes for the preparation of aminoethers
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A process for preparing aminoethers, particularly bis[2-(N,N-dialkylamino)alkyl]ethers, which comprises contacting a carboxylated aminoether with a metal oxide catalyst under conditions effective to produce the aminoether. Many of these aminoethers are useful as catalysts in the production of polyurethanes, especially cellular polyurethanes.
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- Temperature and Pressure Effects on the Reversible Reaction of a Parent Phenol (GH) Corresponding to Galvinoxyl with Aliphatic Amines
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The effects of temperature and pressure on the reversible reaction between GH and aliphatic amines in acetonitrile have been studied spectrophotometrically.The formation of the free ions rather than that of ion pairs has been confirmed by the modified Benesi-Hildebrand (B-H) plot.From the plot the equilibrium constants were estimated.From the temperature dependence of the equilibrium constant (K), the heat and entropy of reactions were estimated to be: (ΔH0)av=-44.5 kJ mol-1, and (ΔS0)av=-193 J K-1 mol-1.From the pressure dependence of K the reaction volume (ΔV0)av was estimated to be -40 dm3 mol-1.When unbranched primary amines were used, a side reaction took place for which an explanation has been given.
- Nishimura, Norio,Iga, Siroh,Satoh, Masahiro,Yamamoto, Shunzo
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p. 2437 - 2441
(2007/10/02)
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- Catalysts for alkoxylation reactions
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Catalysts producing a sharply peaked alkoxylation distribution during the alkoxylation of organic materials comprise mixtures of BF3 and metal alkyls or metal alkoxides, SiF4 and metal alkyls or metal alkoxides, or mixtures of these catalysts.
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- Methods of alkoxylation
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Catalysts comprising mixtures of HF and metal alkoxides and mixed metal alkoxides produce a sharply peaked alkoxylation distribution during the alkoxylation of organic materials.
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- Catalysts for alkoxylation reactions
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Catalysts and a method of using said catalysts for the alkoxylation of a variety of materials is disclosed. Catalysts so described produce alkoxylates having a very sharp alkoxylate distribution. The catalysts are supported and unsupported dialkoxy and dialkyl metal fluorides and halides and alkyl metal difluorides and dihalides.
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- REACTION OF VINYL ESTERS OF α,β-UNSATURATED CARBOXYLIC ACIDS WITH SECONDARY AMINES
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It was established that the double bond of the acrylic system is more reactive in the reactions of vinyl acrylate and allyl acrylate with secondary amines and that the reaction of secondary amines with vinyl trans-crotonate and cinnamate takes place regioselectively at the double bond of the vinyloxy group.Methods were found for the production of vinyl and allyl β-substituted aminopropionates and 2-alkylaminoethyl trans-crotonate and trans-cinnamate.
- Komarova, L. I.,Lomanovskaya, T. D.,Komarov, N. V.
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p. 1624 - 1627
(2007/10/02)
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- Neighboring Group Effects in the β-Halo Amines. Synthesis and Solvolytic Reactivity of the anti-4-Substituted 2-Azaadamantyl System
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The syntheses of anti-4-chloro-2-n-propyl-2-azaadamantane (1) and 2-(2-chloroethyl)-2-azaadamantane (8) were carried out.When 1 was subjected to solvolysis in aqueous methanolic NaOH, a rate enhancement of ca. 2*106 was observed at 25 deg C, compared to that for 2-chloroadamantane (23).The solvolytic rate of 1 is comparable to that of an aliphatic β-halo amine, and because of the absence of a kinetic rate component due to solvent assistance in the adamantyl system, the observed enhancement may represent the rate-limiting case for the substituted β-chloroethylamines.The solvolysis rate of 8 was 2.5-fold less than that of 1, despite an expected decrease in activation energy.The lower rate for 8 may be due to its larger negative entropy of activation compared to that of 1.Indirect evidence was found for the existence of azridinium ion intermediates during solvolysis, but their direct observation remains to be accomplished.
- Henkel, James G.,Faith, William C.
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p. 4953 - 4959
(2007/10/02)
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- CLEAVAGE OF N-METHOXYMETHYLAMMONIUM SALTS. III. TRANSFORMATION OF AMMONIUM SALT DERIVATIVES OF ALIPHATIC AMINO ALCOHOLS IN DIMETHYL SULFOXIDE
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The dealkylation of methoxymethyl quaternary ammonium salts of some aliphatic amino alcohols in DMSO leads to the simultaneous formation of the hydrohalides of methyl(aminoalkyl)formals and the corresponding amino alcohols.The formals are formed by an intermolecular mechanism.
- Bystrova, L. P.,Kuznetsov, S. G.,Chigareva, S. M.
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p. 1549 - 1553
(2007/10/02)
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- 2'-(4,6-Disubstituted)-s-triazin-2-yl)amino-6'-dialkylamino flurans
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Fluorans useful as color precursors, particularly in the art of carbonless duplicating are normally colorless and are represented by the structural formula STR1 wherein R represents non-tertiary alkyl of one to four carbon atoms; R1 and R2 represent hydrogen or non-tertiary alkyl of one to four carbon atoms; R3 and R4 represent chlorine, NH2 or one of the groups --NR5 -(lower-alkylene)-N(R6)(R7), --NR5 -(lower-alkylene-N(R8)(R9)(R10) An, -NR5 -(lower-alkylene)-OH, -NR5 -(lower-alkylene) STR2 --NR5 -(HSO3 -C6 H4) or --O-(lower-alkylene)-N(R8)(R9) in which R5, R6 and R7 represent hydrogen or non-tertiary alkyl of one to four carbon atoms; R8 and R9 represent non-tertiary alkyl of one to four carbon atoms; R10 represents non-tertiary alkyl of one to four carbon atoms, benzyl or benzyl substituted in the benzene ring by one or two of halo or alkyl of one to three carbon atoms; and An represents an anion.
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- Optical brightening agents of naphthalimide derivatives
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A naphthalimide derivative having the formula STR1 wherein R is an alkyl, or cycloalkyl, an aralkyl, a haloalkyl, an alkoxyalkyl, a hydroxyalkyl, an N,N-dialkylaminoalkyl, an unsubstituted or halogen-, alkyl-, alkoxy- or hydroxy-substituted aryl, or an ammoniumalkyl; X is a group of the formula, STR2 wherein A is STR3 or an unsubstituted or halogen-substituted arylene, or a group of the formula, STR4 wherein R1 is hydrogen, an alkyl, phenyl, a hydroxyalkyl, or an alkoxyalkyl; Y is --CO--, --COO--, --CONR3 -- (where R3 is hydrogen or an alkyl), or --SO2 --; R2 is hydrogen, an alkyl, a cycloalkyl, an aralkyl, a haloalkyl, an alkyl- or aryl-substituted amino-alkyl, an unsubstituted or halogen-, alkyl-, alkoxy-, hydroxy-, amino- or alkylamino-substituted aryl, a group of the formula, STR5 (where R, R1 and Y are as defined above and R4 is a bivalent group), or a group of the formula, (where R5 is direct linkage or a bivalent group; Q+ is a substituted ammonium, a cycloammonium or a hydrazinium; and α- is an anion), Which is useful for optically brightening an organic polymer material.
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- Extremely low viscosity adducts of lactams with alcohols
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Adducts useful as solvents are prepared from lactams and an aliphatic, cycloaliphatic or araliphatic alcohol or thioalcohol. Solutions of the adducts in the lactam, alcohol or thioalcohol are also disclosed as well as a process for preparing the adducts and solutions thereof.
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