Pyrrolidones, preparation

Polyfvinyl pyrrolidone), prepared from iV-vinylpyrrolidone, is used both in cosmetics and as a synthetic blood substitute. Draw a representative segment of the polymer. 

Table 4.9. Azo groups-containing poly(l-vinyl-2-pyrrolidone) prepared from 11.1 g VP (0.1 Mol) in bezene (33.3g)59)...

M. Ignatova, N. Manolova, I. Rashkov, Novel antibacterial fibers of quaternized chitosan and poly (vinyl pyrrolidone) prepared by electrospinning, Eur. Polym. J. 43 (2007) 1112-1122. 

HOCH2CH2CH2CH2OH. B.p. 228"C. Prepared ethyne plus methanal, hydrogenated to butanediol. Used in production of y-buty-rolactone and 2-pyrrolidone. Widely used in polyurethane products, butylenes See butenes. 

A/ -Methoxycarbonyl-2-pyrroline undergoes Vilsmeier formylation and Friedel-Crafts acylation in the 3-position (82TL1201). In an attempt to prepare a chloropyrroline by chlorination of 2-pyrrolidone, the product (234) was obtained in 62% yield (8UOC4076). At pH 7, two molecules of 2,3-dihydropyrrole add together to give (235), thus exemplifying the dual characteristics of 2,3-dihydropyrroles as imines and enamines. The ability of pyrrolines to react with nucleophiles is central to their biosynthetic role. For example, addition of acetoacetic acid (possibly as its coenzyme A ester) to pyrroline is a key step in the biosynthesis of the alkaloid hygrine (236). 

The successful development of eye contact lenses led in turn to a demand for soft contact lenses. Such a demand was eventually met by the preparation of copolymers using a combination of an acrylic ester monomer such as methyl methacrylate, a cross-linkable monomer such as a dimethacrylate, and a monomer whose homopolymer is soluble or highly swollen in water such as N-vinyl pyrrolidone. Such copolymers swell in water (hence the term hydrophilic), the degree of swelling being controlled by the specific type and amount of the monomers used. In use the lens is swollen to equilibrium in water, a typical soft lens having a water content of about 75%. 

The monomer is prepared from acetylene, formaldehyde and ammonia via but-2-yne-1,4-diol, butane-1,4-diol, y-butyrolactone and y-pyrrolidone (Figure 17.8). 

The treatment of esters of aromatic acids with l-alkyl-2-pyrrolidones and l-alkyl-2-piperidones is an extremely useful method for the preparation of simple pyrrolines and piperideines, respectively. The l-alkyl-3-aroyl-2-... 

During a study of azonitrones (70), Forrester and Thomson showed that reaction with toluene-p-sulfinic acid resulted in nitrogen evolution and formation of the hydroxamic acid (66) together with the pyrrolidone (71) and the amidine (72). These workers suggested the following reaction course. Although the yield of hydroxamic acid was high, the method is not likely to be of preparative value. 

Several wide-porous affinity and size-exclusion chromatographic supports were prepared by Ivanov, Zubov et al. by means of acylation of aminopropyl-glass supports by copolymers of N-vinyl pyrrolidone (N-VP,1) and acryloyl chloride (AC,2), M = 7700 and 35000 respectively [50, 51]. The copolymers prepared by free radical copolymerization contain their units almost in equimolar proportion, with high tendency to alternation expected from the copolymerization parameters (rj = 0.035, r2 = 0.15 [52]). Residual carbonyl chloride groups of the chemisorbed copolymer could be transformed to 2-hydroxyethylamides which were solely... 

Galactosylated chitosan prepared from lactobionic acid and chitosan with l-ethyl-3-(3-dimethylaminopropyl)-carbodiimideand N-hydroxysuccinimide was a good extracellular matrix for hepatocyte attachment [155] (Fig. 4). Furthermore, graft copolymers of galactosylated chitosan with poly(ethylene glycol) or poly(vinyl pyrrolidone) were useful for hepatocyte-targeting DNA carrier [156,157]. 

XRD analysis of the solid product showed three main peaks at 28.5 , 47.4 and 56.3 , which indicated that pure crystalline CuCl was formed [3]. Several well-known dispersants polyvinyl pyrrolidone (PVP), sodium hexameta phosphate (SHP), the sodium salt of EDTA (EDTA-Na), sodium dodecyl sulfonate (SDS), and sodium dodecyl benzene sulfonate (SDBS), were introduced to obtain a highly dispersed catalyst. The X-ray patterns obtained with these were basically the same as the patterns obtained with the solids prepared in the other experiments described here. 

Pt/Pd bimetallic nanoparticles can be prepared by refluxing the alcohol/water (1 1, v/v) solution of palla-dium(II) chloride and hexachloroplatinic(IV) acid in the presence of poly(A-vinyl-2-pyrrolidone) (PVP) at ca. 95 °C for Ih [15,16,48]. The resulting Pd/Pt nanoparticles have a Pt-core/Pd-shell structure with a narrow size distribution and the dispersion is stable against aggregation for several years. The core/shell structure was confirmed by the technique of EAXFS. Composition of Pt/Pd nanoparticles can be controlled by the initially feed amount of two different metal ions, i.e., in this case one... 

In Figure 12a (Pd Pt = 1 2) and 12b (Pd Pt = 1 1), only the spectral feature of CO adsorbed on the Pt atoms, i.e., a strong band at 2068 cm and a very weak broad band at around 1880 cm was observed, while that derived from CO adsorbed on Pd atoms at 1941 cm is completely absent, which proved that the Pd-core has been completely covered by a Pt-shell. Recently we also characterized Au-core/Pd-shell bimetallic nanoparticles by the CO-IR [144]. Reduction of two different precious metal ions by refluxing in ethanol/ water in the presence of poly(A-vinyl-2-pyrrolidone) (PVP) gave a colloidal dispersion of core/shell structured bimetallic nanoparticles. In the case of Pd and Au ions, the bimetallic nanoparticles with a Au-core/Pd-shell structure are usually produced. In contrast, it is difficult to prepare bimetallic nanoparticles with the inverted core/shell, i.e., Pd-core/Au-shell structure. A sacrificial hydrogen strategy is useful to construct the inverted core/shell structure, where the colloidal dispersions of Pd cores are treated with hydrogen and then the solution of the second element, Au ions, is slowly... 

We first prepared gold clusters stabilized by conventional water-soluble pol5mer, FVF (FVF = poly(V-vinyl-2-pyrrolidone), M = 40kDa) [21]. 

Homopolymers and copolymers from amido-sulfonic acid or salt containing monomers can be prepared by reactive extrusion, preferably in a twin screw extruder [1660]. The process produces a solid polymer. Copolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium-2-acrylamido-2-methyl-propane sulfonate have been proposed to be active as fluid loss agents. Another component of the formulations is the sodium salt of naphthalene formaldehyde sulfonate [207]. The fluid loss additive is mixed with hydraulic cements in suitable amounts. 

This study involved the preparation and characterization of poly(N-phenyl 3,4-dimethylenepyrrolidine) and the subsequent oxidation and reduction of this polymer. The parent polymer was not very soluble, so it was difficult to characterize. However, after oxidizing in the presence of palladium on carbon in nitrobenzene, the resultant poly(N-phenyl 3,4-dimethylenepyrrole) was soluble in several organic solvents. Attempts to reduce the original polymer to the pyrrolidone were unsuccessful. 

Preparation of the quaternary anticholinergic agent benzilonium bromide (47) is begun by conjugate addition of ethylamine to methylacrylate, giving aminoester 42. Alkylation of 42 with methyl bromo-acetate leads to diester 43, which is transformed into pyrrolidone 44 by Dieckmann cyclization, followed by decarboxylation. Reduction of 44 by lithium aluminum hydride leads to the corresponding amino-alcohol (45). Transesterification of alcohol 45 with methyl benzilate leads to 46. Benzilonium bromide (47) is obtained by alkylation of ester 46 with ethyl bromide. 2... 

A more highly substituted pyrrolidone, doxapram, shows activity as a respiratory stimulant. Preparation of this agent involves an interesting rearrangement, which in effect results in a ring exchange reaction. Alkylation of the anion from diphenylacetonitrile with the chloropyrrolidine 14 affords 15. Hydrolysis of the nitrile function leads to the... 

Li, Z Sun, Q. and Gao, M.Y. (2005) Preparation of water-soluble magnetite nanocrystals from hydrated ferric salts in 2-pyrrolidone mechanism leading to Fe304. Angewandte Chemie International Edition, 44 (1), 123-126. 

The heteroatom-assisted Diels-Alder reaction has emerged as an extremely powerful method for the preparation of complex heterocycles. In several cases, such reactions with TADs are described. For example, the reaction of vinyl pyrrolidone 594 with MTAD provides a 7 2 mixture of diastereomers 595 and 596 in 95% combined yield, showing only low face selectivity (Equation 88) <2005JOC5221>. 

The electrode active masses were prepared by mixing the active material with 10 wt.% of polyvynilidene fluoride slurred in 1-methyl-pyrrolidone solvent. The actual mass was then pasted onto one side of precleaned Co foil, dried for 4 h at 100°C, pressed and the disks of 15,6 mm diameter were cut and placed into the cell s coins. Large excess of Li metal (foil) was used as a counter electrode. 1M LiPF6 solution in mixture of ethylene carbonate (50 vol.%) and methyl carbonate was used as an electrolyte (Merck product LP30). 

In 1968, a French Patent issued to the Sumitomo Chemical Company disclosed the polymerization of several vinyl monomers in C02 [84], The United States version of this patent was issued in 1970, when Fukui and coworkers demonstrated the precipitation polymerization of several hydrocarbon monomers in liquid and supercritical C02 [85], As examples of this methodology, they demonstrated the preparation of the homopolymers PVC, PS, poly(acrylonitrile) (PAN), poly(acrylic acid) (PAA), and poly(vinyl acetate) (PVAc). In addition, they prepared the random copolymers PS-co-PMMA and PVC-co-PVAc. In 1986, the BASF Corporation was issued a Canadian Patent for the preparation of polymer powders through the precipitation polymerization of monomers in carbon dioxide at superatmospheric pressures [86], Monomers which were polymerized as examples in this patent included 2-hydroxyethylacrylate and iV-vinylcarboxamides such as iV-vinyl formamide and iV-vinyl pyrrolidone. 

PEG, 13 736-737 pH-sensitive, 13 743 PHEMA, 13 733-734, 749, 750 poly(acrylamide)-based, 13 737-738 poly(acrylic/methacrylic acid), 13 734 poly(N-vinyl 2-pyrrolidone), 13 739 polyurethane, 13 739 porous, 13 750-751 preparation methods for, 13 731-732 properties and preparation of,... 

In order to evaluate the catalytic characteristics of colloidal platinum, a comparison of the efficiency of Pt nanoparticles in the quasi-homogeneous reaction shown in Equation 3.7, with that of supported colloids of the same charge and of a conventional heterogeneous platinum catalyst was performed. The quasi-homogeneous colloidal system surpassed the conventional catalyst in turnover frequency by a factor of 3 [157], Enantioselectivity of the reaction (Equation 3.7) in the presence of polyvinyl-pyrrolidone as stabilizer has been studied by Bradley et al. [158,159], who observed that the presence of HC1 in as-prepared cinchona alkaloids modified Pt sols had a marked effect on the rate and reproducibility [158], Removal of HC1 by dialysis improved the performance of the catalysts in both rate and reproducibility. These purified colloidal catalysts can serve as reliable... 

Polyvinyl alcohol (PVA), which is a water soluble polyhidroxy polymer, is one of the widely used synthetic polymers for a variety of medical applications [197] because of easy preparation, excellent chemical resistance, and physical properties. [198] But it has poor stability in water because of its highly hydrophilic character. Therefore, to overcome this problem PVA should be insolubilized by copolymerization [43], grafting [199], crosslinking [200], and blending [201], These processes may lead a decrease in the hydrophilic character of PVA. Because of this reason these processes should be carried out in the presence of hydrophilic polymers. Polyfyinyl pyrrolidone), PVP, is one of the hydrophilic, biocompatible polymer and it is used in many biomedical applications [202] and separation processes to increase the hydrophilic character of the blended polymeric materials [203,204], An important factor in the development of new materials based on polymeric blends is the miscibility between the polymers in the mixture, because the degree of miscibility is directly related to the final properties of polymeric blends [205],... 

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