2-Pyrrolidone N-methyl

It is evident that many solvents present considerable health hazards and hence have been subject to restriction through regulation. Even when using solvents of low toxicity, their odor may be undesirable in both the working environment and in the area around manufacturing facilities. The common modes of entry of these volatile substances in the body are inhalation, skin contact and ingestion. The toxic effects of solvents depend on the amount of solvent and the exposure time, based on which degree of toxicity is represented, as follows. 

Acute toxicity represents the acute damage that may occur under short-term exposure to high solvent doses, which can be particu-lariy important in cases of accidental ingestion or spiiis. 

Chronic toxicity represents the chronic damage and sensitization that may occur as a result of the absorption of smaller amounts over a longer period of time. Chronic effects are more dangerous since they are often not detected early enough and may lead to health risks such as cancer. 

The risk to human health can be minimized by proper personal safety precautions and the use of protective clothing and equipment, such as gloves, goggles, organic vapor masks, or even complete air-fed suits with visors for spray application in enclosed areas that are also ventilated to prevent build-up of vapor. 

Lethal dosage values (LDjg based on oral administration to rats) of solvents are used to represent their toxicities. Lethal concentration values (LCjq) are also being used because, in most cases, solvent poisoning is caused by inhalation of solvent vapor. 

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It has been demonstrated that a solvent-extraction procedure with N-methyl pyrrolidone is capable of producing coal-derived extract pitches with low-ash contents. Moreover, the properties of the pitches can be varied by partial hydrogenation of the coal prior to extraction. The yield of the pitches along with the physical and chemical properties of the cokes and graphites vai in an understandable fashion. 

N-Methyl pyrrolidone, dibasic ethers, and organic esters, substituting for more hazardous paint removers (Paint Removers, 1991 Davis et al., 1994)... 

Aprotic polar solvents have to be used for several reasons. They are often good solvents for both monomers (including phenolates) and amorphous polymers. In addition, they can also stabilize the Meisenheimer intermediates. Common aprotic polar solvents, such as DMSO, /V,/V-dimcthyl acetamide (DMAc), DMF, N-methyl pyrrolidone (NMP), and cyclohexylpyrrolidone (CHP) can be used. Under some circumstances, very high reaction temperature and boiling point solvents such as sulfolane and diphenyl sulfone (DPS) have to be used due to the poor reactivity of the monomers or poor solubility of the resulting, possibly semicrystalline polymers, as in the PEEK systems. 

Die Reduktion von 9-Brom-ll/3-hydroxy-steroiden mit Chrom(II)-Salzen, insbeson-dere mit Chrom(II)-acetat fiihrt zu 11/3-Hydroxy-steroiden (s. S.515), A9 (11)-Ste-roiden (s. S.518) und 5,9-Cyclo-steroiden. Die Cyclopropan-Bildung wird durch Chrom(II)-acetat in Dimethylsulfoxid bzw. Dimethylformamid begiinstigt. So laufen beim 9a-Brom-l l/3-hydroxy-3-oxo-l 7/ -acetyl-ostren-(510) in waBr. Aceton, THF, 1,4-Di-oxan oder N-Methyl-pyrrolidon Substitution, Eliminierung und Cyclisierung nebeneinan-der ab, in Dimethylsulfoxid oder Dimethylformamid erhalt man fast ausschlieBlich ///3-Hydroxy-3-oxo-17 3-acetyl-5,9-cyclo-dstran5 ... 

Cyanations of quinoline 877 and isoquinoline N-oxide 879 in DMF or N-methyl-pyrrolidone provides the cyano compounds 878 and 880 in 90 and 79% yield, respectively (Scheme 7.4) it was expected, e.g., that pyrimidine N-oxides would react analogously [6]. 

In recent years researchers at West Virginia University have developed coal-derived pitches on a laboratory scale in quantities sufficient to make 1 kg samples of calcined coke for fashioning graphite test specimens. The pitches were derived by utilizing solvent extraction with N-methyl pyrrolidone (NMP). This solvent is able to isolate coal-based pitches m high yield and with low mineral matter content [13]. It is this work that will form the basis of the discussion for the later part of this chapter. 

DISTAPEX A process for removing aromatic hydrocarbons from pyrolysis gasoline or coke-oven benzole by extractive distillation with added N-methyl pyrrolidone. The operating temperature is at least 170°C. Developed by Lurgi. First announced in 1961 by 1993, 22 plants had been built. 

EXOL N Also called EXOL N Extraction. A solvent extraction process for purifying feedstocks for making lubricating oil. The solvent is N-methyl pyrrolidone. Developed and licensed by Exxon Research Engineering Compary. Seventeen units had been installed by 1994. 

When dopa was oxidized using the PIPo-Cu catalyst, the distinguished acceleration was observed as compared with the PVIm-Cu or imidazole-Cu catalysts (Fig. 6). An increase in content of the N-vinylpyrrolidone residue in the PIPo copolymer caused higher activity of the Cu complex for the dopa oxidation. The similar acceleration was also produced when N-methyl-pyrrolidone was added to the system of PVIm-Cu. However, nearly 103 fold concentration of the pyrrolidone residue was necessary as compared with the PIPo copolymer. Addition of homopolymer of N-vinyl-pyrrolidone to PVIm-Cu caused no acceleration. 

Solvent extraction of benzene works the same way. But instead of water, the various solvents used are sulfolane, liquid SO2, diethylene-glycol, and NMP (N-methyl pyrrolidone). The paint thinner/salt/water process described above might be called a batch solvent process, since it consists of sequential steps that can be repeated, batch after batch. Some low-volume commercial processes still operate that way. 

Like the solvent extraction process, extractive distillation relies on the intimate contact of the liquid solvent and the aromatics concentrate vapors to allow the aromatics to be preferentially dissolved in the solvent. The usual list of solvents includes DEG (Diethylene glycol), TEG (Triethylene glycol), NMP (N-methyl pyrrolidone), or methyl formamide. 

Arosolvan A solvent extrachon process for removing aromatic hydrocarbons from petroleum mixtures, using N-methyl pyrrolidone (NMP) containing 12 to 14 percent water at 20 to 40°C. Developed by Luigi, and first used commercially in Japan in 1961. 

Typically, this rearrangement process is catalyzed by an inorganic Lewis acid and inorganic or quaternary onium iodide in a polar, aprotic solvent (e.g., ZnR, KI, N-methyl pyrrolidone) (8,9). For years, however, commercial processes utilizing this chemistry were unattractive due to the high cost of 1 and poor reaction selectivity. 

The viscosity of emulsions obtained from two mutually incompatible polymers dissolved in a common solvent was studied by a falling ball viscometer, a cone-plate viscometer, and a capillary viscometer. The two polymers are polyacrylonitrile and polyurethane, and the solvent is N-methyl-pyrrolidone. The measurements are compared with theory, and a model is proposed for the development of a stationary pressure flow of an emulsion in a capillary. 

Solvent/nonsolvent system. The solvent must be miscible with the nonsolvent (here an aqueous system). An aprotic polar solvent like N-methyl pyrrolidone (NMP), dimethyl formamide (DMF), dimethyl acetamide (DMAc) or dimethylsulfoxide (DMSO) is preferable for rapid precipitation (instantaneous demixing) upon immersion in the nonsolvent water. As a consequence, a high porosity anisotropic... 

More than 4.5 million metric t of solvents is used in the United States annually, and it has been suggested by industry experts that ethyl lactate could replace conventional solvents in more than 80% of these applications (34). Vertec Biosolvents Inc. is currently using ethyl lactate in soy oil-solvent blends. Applications targeted by Vertec Biosolvents include conventional solvents that are under environmental scrutiny such as methylene chloride, methyl ethyl ketone, and N-methyl pyrrolidone (36). Table 3 lists the selling prices of some common solvents. 

As shown in Table 4, the real promise of succinic acid lies in its derivatives. A DOE-funded collaboration among Oak Ridge National Laboratory Argonne National Laboratory Pacific Northwest National Laboratory National Renewable Energy Laboratory and Applied CarboChemicals, Inc. investigated succinic acid derivatives such as tetra-hydrofuran, 1,4-butanediol, y-butyrolactone, and N-methyl pyrrolidone. More recently, Applied Carbochemicals has pursued succinate salts that can serve as de-icers and herbicide additives (40,41). 

N-Methyl pyrrolidone 50,900 Could be displaced by ethyl lactate... 

This consisted of acetone, xylene, and N-methyl-pyrrolidone. 

Alkalimetall-acylamide (z.B. Kalium-phthalimid) werden in polaren Losungsmitteln (N-Methyl-pyrrolidon) mit Thiophosphorsaure-chlorid-0,0-diestem zu Thiophosphor-saure-acylamid-0,0-diestern (—50%) umgesetzt413. Mit 1-Methyl-imidazol als Ka-talysator erhohen sich die Ausbeuten z.B. Thiophosphorsiiure-0,0-diethylester-phthalimid (-85% Schmp. 81-83°)414 ... 

A similar procedure was used with co-dicarboxy-PMMA macromonomers 105). They were mixed with another diacid (sebacic acid) and reacted stoichiometrically with a diamine (p,p -diaminodiphenylmethane and others) at 100 °C in N-methyl-pyrrolidone/pyridine mixtures. The formed polyamide was shown to contain PMMA grafts although the proportion of MMA was slightly lower than in the feed. 

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