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Pyridine toxicity

Synonym 1,2-ethanediol Formula HOCH2CH2OH MW 62.07 CAS [107-21-1] used as antifreeze in cooling and heating systems and in hydraulic brake fluids colorless liquid sweet taste hygroscopic density 1.11 g/mL boils at 197.5°C freezes at -13°C highly soluble in water, lower alcohols, acetone, and pyridine toxic. [Pg.333]

Huh and coworkers (1986) have investigated the effect of glycyrrhetinic acid [471-53-4] on pyridine toxicity in mice. Pretreatment with glycyrrhetinic acid decreased depression of the central nervous system and mortality in animals induced by pyridine. Such pretreatment markedly decreased the activity of the enzyme serum transaminase [9031-66-7], and increased the activity of hepatic microsomal aniline hydroxylase [9012-90-0], a pyridine- metabolizing enzyme. [Pg.486]

Detoxifica.tlon. Detoxification systems in the human body often involve reactions that utilize sulfur-containing compounds. For example, reactions in which sulfate esters of potentially toxic compounds are formed, rendering these less toxic or nontoxic, are common as are acetylation reactions involving acetyl—SCoA (45). Another important compound is. Vadenosylmethionine [29908-03-0] (SAM), the active form of methionine. SAM acts as a methylating agent, eg, in detoxification reactions such as the methylation of pyridine derivatives, and in the formation of choline (qv), creatine [60-27-5] carnitine [461-06-3] and epinephrine [329-65-7] (50). [Pg.379]

Solubility and Solvent Resistance. The majority of polycarbonates are prepared in methylene chloride solution. Chloroform, i7j -l,2-dichloroethylene, yy -tetrachloroethane, and methylene chloride are the preferred solvents for polycarbonates. The polymer is soluble in chlorobenzene or o-dichlorobenzene when warm, but crystallization may occur at lower temperatures. Methylene chloride is most commonly used because of the high solubiUty of the polymer (350 g/L at 25°C), and because this solvent has low flammabiUty and toxicity. Nonhalogenated solvents include tetrahydrofuran, dioxane, pyridine, and cresols. Hydrocarbons (qv) and aUphatic alcohols, esters (see Esters, organic), or ketones (qv) do not dissolve polycarbonates. Acetone (qv) promotes rapid crystallization of the normally amorphous polymer, and causes catastrophic failure of stressed polycarbonate parts. [Pg.279]

Most of them are generally classified as poisons. Exceptions to this rule are known. A notable one is 4-dimethyl aminopyridine (DMAP) (24), which is widely used in industry as a superior acylation catalyst (27). Quaternary salts of pyridines are usually toxic, and in particular paraquat (20) exposure can have fatal consequences. Some chloropyridines, especially polychlorinated ones, should be handled with extra care because of their potential mutagenic effects. Vinylpyridines are corrosive to the skin, and can act as a sensitizer for some susceptible individuals. Niacin (27), niacinamide (26), and some pyridinecarbaldehydes can cause skin flushing. [Pg.335]

Many other compounds are presendy in use a 1993 database search showed 27 active ingredients in 212 products registered by the U.S. EPA for human use as repellents or feeding depressants, including octyl bicycloheptene dicarboxamide (A/-2-ethylhexylbicyclo[2.2.1]-5-hepten-2,3-dicarboxamide), dipropyl isocinchomeronate (2,5-pyridine dicarboxyhc acid, dipropyl ester), dimethyl phthalate, oil of citroneUa, cedarwood oil, pyrethrins, and pine tar oil (2). Repellent—toxicant or biting depressant systems are available which are reasonably comfortable for the user and can protect completely against a number of pests for an extended period of time (2). [Pg.112]

Sulfur trioxide reactivity can also be moderated through the use of SO adducts. The reactivity of such complexes is inversely proportional to their stabihty, and consequentiy they can be selected for a wide variety of conditions. Whereas moderating SO reactivity by adducting agents is generally beneficial, the agents add cost and may contribute to odor and possible toxicity problems in derived products. CeUulosic material has been sulfated with SO.—trimethyl amine adduct in aqueous media at 0 to 5°C (16). Sulfur trioxide—triethyl phosphate has been used to sulfonate alkenes to the corresponding alkene sulfonate (17). Sulfur trioxide—pyridine adduct sulfates oleyl alcohol with no attack of the double bond (18). [Pg.77]

Cyanide compounds are classified as either simple or complex. It is usually necessary to decompose complex cyanides by an acid reflux. The cyanide is then distilled into sodium hydroxide to remove compounds that would interfere in analysis. Extreme care should be taken during the distillation as toxic hydrogen cyanide is generated. The cyanide in the alkaline distillate can then be measured potentiometricaHy with an ion-selective electrode. Alternatively, the cyanide can be determined colorimetricaHy. It is converted to cyanogen chloride by reaction with chloramine-T at pH <8. The CNCl then reacts with a pyridine barbituric acid reagent to form a red-blue dye. [Pg.232]

Specifications, Analysis, and Toxicity. Dicyandiamide is identified quaHtatively by paper chromatography and quantitatively by ultraviolet spectrometry of the chromatogram. More commonly, total nitrogen analysis is used as a purity control or the dicyandiamide is converted by hydrolysis to guanylurea, which is determined gravimetrically as the nickel salt (50). Methods based on the precipitation of silver dicyandiamide picrate are sometimes used (51). Dicyandiamide can also be titrated with tetrabutylammonium hydroxide ia pyridine solution. Table 4 gives a typical analysis of a commercial sample. Dicyandiamide is essentially nontoxic. It may, however, cause dermatitis. [Pg.371]

Carbazole-9-carbonyl chloride [73500-82-0J M 300.0, m 100-103 , 103.5-104.5 . Recrystd from C6H6. If it is not very pure (presence of OH or NH bands in the IR) dissolve in pyridine, shake with phosgene in toluene, evaporate and recrystallise the residue. Carry out this experiment in a good fume cupboard as COCI2 is very TOXIC, and store the product in the dark. It is moisture sensitive. The amide has m 246.5-247 , and the dimethylaminoethylamide hydrochloride has m 197-198 . [Weston et al. J Am Chem Soc IS 4006 1953.]... [Pg.156]

NOTE - Petrochemical plants also generate significant amounts of solid wastes and sludges, some of which may be considered hazardous because of the presence of toxic organics and heavy metals. Spent caustic and other hazardous wastes may be generated in significant quantities examples are distillation residues associated with units handling acetaldehyde, acetonitrile, benzyl chloride, carbon tetrachloride, cumene, phthallic anhydride, nitrobenzene, methyl ethyl pyridine, toluene diisocyanate, trichloroethane, trichloroethylene, perchloro-ethylene, aniline, chlorobenzenes, dimethyl hydrazine, ethylene dibromide, toluenediamine, epichlorohydrin, ethyl chloride, ethylene dichloride, and vinyl chloride. [Pg.57]

TsCl, DABCO, CH2CI2, MTBE or AcOEt, 45-97% yield. In many cases, these conditions were found to be superior to the use of pyridine as a base. DABCO is also less toxic than pyridine, which may prove useful in a commercial setting. [Pg.199]

Little has been published on the toxicity of simple isothiazoles except that isothiazole itself is much more toxic than pyridine. More complex isothiazoles are undoubtedly less toxic. [Pg.120]

Second generation COMT inhibitors were developed by three laboratories in the late 1980s. Apart from CGP 28014, nitrocatechol is the key structure of the majority of these molecules (Fig. 3). The current COMT inhibitors can be classified as follows (i) mainly peripherally acting nitrocatechol-type compounds (entacapone, nitecapone, BIA 3-202), (ii) broad-spectrum nitrocatechols having activity both in peripheral tissues and the brain (tolcapone, Ro 41-0960, dinitrocatechol, vinylphenylk-etone), and (iii) atypical compounds, pyridine derivatives (CGP 28014,3-hydroxy-4-pyridone and its derivatives), some of which are not COMT inhibitors in vitro but inhibit catechol O-methylation by some other mechanism. The common features of the most new compounds are excellent potency, low toxicity and activity through oral administration. Their biochemical properties have been fairly well characterized. Most of these compounds have an excellent selectivity in that they do not affect any other enzymes studied [2,3]. [Pg.336]

Succinic acid, 2,2-difluoeo-, 42, 44 SuCCINIMIDE, N-IODO-, 42, 73 Sulfonation of pyridine, 43, 97 Sulfur tetrafluoride, in conversion of carboxylic acids to 1,1,1-trifluoro compounds, 41, 104/ toxicity of, 41,105 / ... [Pg.123]

The hydrogen chloride is removed either by reduced pressure or by salt formation with pyridine or sodium bicarbonate the latter procedure gave high yields of the pure ester. Toy (47) also measured the hydrolysis rates and compared the toxicities of a series of tetraalkyl pyrophosphates. Of these tested, the tetraethyl ester was the most toxic to white mice. [Pg.155]

Tetraisopropyl Pyrophosphate. This ester, a water-white liquid, has been prepared by Toy (47) in 94% yield from diisopropyl chlorophosphate and water in the presence of pyridine. The ester is insecticidal and is about one tenth as toxic to white mice as tetraethyl pyrophosphate. An insecticidal dust of much greater stability than tetraethyl pyrophosphate dust can be formulated from tetraisopropyl pyrophosphate, inasmuch as the tetraisopropyl ester hydrolyzes at approximately V50th the rate at which the tetraethyl ester breaks down in the presence of moisture. [Pg.158]

The deployment of chromium(VI) reagents in the oxidative transformation is compromised due to inherent toxicity, involved preparation of its various complex forms (with pyridine or acetic acid) and cumbersome workup procedures. Chromium trioxide (Cr03) immobilized on premoistened alumina enables efficient oxidation of ben -... [Pg.196]


See other pages where Pyridine toxicity is mentioned: [Pg.486]    [Pg.494]    [Pg.395]    [Pg.486]    [Pg.494]    [Pg.395]    [Pg.124]    [Pg.128]    [Pg.334]    [Pg.334]    [Pg.346]    [Pg.785]    [Pg.836]    [Pg.128]    [Pg.105]    [Pg.479]    [Pg.113]    [Pg.60]    [Pg.122]    [Pg.56]    [Pg.45]    [Pg.870]    [Pg.148]    [Pg.232]    [Pg.546]    [Pg.120]    [Pg.1230]    [Pg.180]    [Pg.443]    [Pg.828]    [Pg.228]    [Pg.247]    [Pg.895]    [Pg.1162]    [Pg.127]   
See also in sourсe #XX -- [ Pg.395 ]




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