Pyridine-3-methanol

Figure 3 Pyridine-methanol dimer model used to evaluate the effect of the hydrogen bonding on the chemical shift principal components of aromatic nitrogens.

A simple example of a bioprecursor prodrug is found in dexpanthenol and 3-pyridine-methanol (Figure 36.27). These... 

FIGURE 36.27 Dexpantiienol and 3-pyridine-methanol are pro-vitamins yielding again the parent molecules after in vivo oxidation. 

A simple example of bioprecursor prodrug is found in dexpanthenol and 3-pyridine-methanol (Fig. 33.26). These primary alcohols are the reduced forms of the vitaminic factors pantothenic acid and nicotinic acid, respectively. Dexpanthenol has the advantage over the parent drug of being more stable, especially towards racemization. 

CAS 100-55-0 EINECS/ELINCS 202-864-6 Synonyms 3-Hydroxymethylpyridine w-Hydroxy-3-picoline Nicotinic alcohol Nicotinyl alcohol p-Picolyl alcohol Pyridine-3-carbinol 3-Pyridine methanol Pyridylcarbinol 3-Pyridylcarbinol 3-Pyridylmethanol... 

Pyridine methanol. See Pyridine-3-methanol 3-Pyridinemethanol, hydrofluoride. See Nicomethanol hydrofluoride Pyridine, 3-methyl-. See P-Picoline Pyridine, 4-methyl-. Seev-Picoline Pyridine-1-oxide. See Pyridine-N-oxide Pyridine-N-oxide... 

Manuf/Distrib. Aldrich Alfa Aesar Hawks Chem. Co Ltd Raschig Sigma-Aldrich Chemie GmbH/Fluka Sigma 3-Pyridine methanol. See Pyridine-3-methanol Pyridinium, 1-dodecyl-, chloride. See Laurylpyridinium chloride Pyrldlnium, 1-(2-hydroxyethylcarbamoylmethyl)-, chloride, dodecanoate Pyridinium, 1-(2-oxo-2-((2-((1-oxododecyl) oxy) ethyl) amino) ethyl)-, chloride. See Lapyrium chloride Pyridinium propyl sulfobetaine CAS 15471-17-7 EINECS/ELINCS 239491-3... 

Nifurprinol. 6-[2-(5-Nitro-2-furanyl)ethenyl]-2-pyridine methanol, is prepared from 5-nitro-2-furancarboxaldehyde and 6-methyl-2-pyridine methanol (48). The product has been used as an antibacterial in fish diseases. 

Pirmenol. Pirmenol hydrochloride, a pyridine methanol derivative, is a racemic mixture. It has Class lA antiarrhythmic activity, ie, depression of fast inward sodium current, phase 0 slowing, and action potential prolongation. The prolongation of refractory period may be a Class III property. This compound has shown efficacy in converting atrial arrhythmias to normal sinus rhythm (34,35). 

Water with ethanol, n-propanol and isopropanol, tcrt-butanol, propionic acid, butyric acid, pyridine, methanol with methyl iodide, methyl acetate, chloroform,... 

Chemical Name 3,3 -(Dithiodimethylene)bis[5-hydroxy-6-methyl-4-pyridine methanol) Common Name Pyrithioxin... 

The Karl Fischer procedure has now been simplified and the accuracy improved by modification to a coulometric method (Chapter 14). In this procedure the sample under test is added to a pyridine-methanol solution containing sulphur dioxide and a soluble iodide. Upon electrolysis, iodine is liberated at the anode and reactions (a) and (b) then follow the end point is detected by a pair of electrodes which function as a biamperometric detection system and indicate the presence of free iodine. Since one mole of iodine reacts with one mole of water it follows that 1 mg of water is equivalent to 10.71 coulombs. 

An additional contributing factor to the mechanism of the present grafting reaction is the role of radiolytically produced hydrogen atoms. In the radiolysis of binary mixtures of aromatic and aliphatic compounds such as styrene-methanol, the concentration of aromatic strongly influences the G(H2) obtained from the methanol. In the most extensively studied binary mixtures of benzene-methanol (11) and pyridine-methanol (10), it is found that the yield of H atoms is important in determining product yields and types. Small additions (5%) of benzene and pyridine significantly reduce G(H2) from the methanol by scavenging H atoms. Above 5% additive, G(H2) is reduced further, but at a slower rate. These data for benzene-methanol and pyridine-methanol can be extrapolated... 

Further work (10) with acid effects in the radiolysis of binary mixtures such as benzene-methanol and pyridine-methanol indicates that the acid phenomenon is more complicated than the simple H atom model originally developed ( ). These more recent experiments (10) show that whilst increased hydrogen atom yields in the presence of acid enhance the overall grafting yield, other mechanisms also contribute to this acid effect. Thus the acid stability of intermediate radicals (I-III) and also analogous species involving the trunk polymer are important. With radicals (I-III), at low styrene concentrations in methanol, these intermediates (MR-) will predominantly react with other available... 

For the purpose of this discussion, styrene and pyridine may be considered to be structurally analogous since the aromatic ring of styrene is complemented by the electron rich -CH=CH2 group whilst pyridine has the nitrogen lone pair. Acid effects observed in the pyridine-methanol system may thus be extrapolated to styrene-methanol. In separate studies, it has been shown that inclusion of acid increased the quantities of scavenging products, pyridyl methanol and methylpyridine. In addition, one scavenging product, pyridylethanol, disappeared and was replaced by a number of unidentified products when acid was included in the radiolysis... 

The behavior of Diels-Alder adducts substituted at the C(3) position (313) is different because the substituent has to prevent an aromatization. Treatment of triketone 313 with pyridine-methanol (1 1, v/v) at 22 °C results in the expected [l,5]-acetyl shift and gives a good yield of the triketone 314, which isomerizes smoothly when heated in the same medium at 65 °C to furnish dihydronaphthalene 315 (equation 109)168. Similar treatment of the triketone 316 affords the bicyclic product 318 rather than 319, presumably via the intermediate 317 (equation 110)168. 

To a saturated solution of 5.5 g. (0.028 mole) of finely powdered cupric acetate monohydrate (Note 1) in 20 riil. of a 1 1 by volume pyridine-methanol mixture (Notes 2, 3, 4, and 5) contained in a 50-ml. round-bottomed flask fitted with a reflux condenser is added 2.0 g. (0.0196 mole) of phenylacetylene (Note 6). The deep-blue suspension becomes green when heated under reflux. After 1 hour of heating, the solution is cooled (Note 7) and added dropwise to 60 ml. of 18N sulfuric add, with stirring and external cooling in an ice-salt freezing mixture (Note 8). The resulting white suspension is extracted with three 25-ml. portions of ether, and the combined ethereal extracts are washed with 15 ml. of... 

Ketones are obtained from a-diketones by reduction with hydrogen sulfide in a pyridine-methanol solution [237], by refluxing with 47% hydriodic acid in acetic acid (yield 80%) [916], and by decomposition of monohydrazones with alkali [923]. Reduction of a-diketones to hydrocarbons is achieved by decomposition of bis-hydrazones by alkali [923]. 

The IR spectra of all three polymers are recorded and compared with one another.The incorporation of monomeric units of 4-vinylpyridine can also be demonstrated by nitrogen analysis of the block copolymer.The solubility behavior is also determined. Po-ly(4-vinylpyridine) is soluble in pyridine, methanol, and chloroform, but insoluble in toluene and diethyl ether it swells considerably in water. On the other hand, the block copolymer, like polystyrene, is soluble in pyridine, chloroform, and toluene but unlike polystyrene, it swells significantly in methanol. 

Pyridine-Methanol 1 1 mix equal volumes of reagent quality of each solvent containing less than 0.10% water. This must be maintained in a protected system... 

It can also be used for rapid detn of small amts of water in miscellaneous materials. The KF reagent consists of sulfur dioxide-iodine in pyridine-methanol solution. It is available in commerce in strength equivalent to 5—6 mg water per 1 ml of reagent. It can also be prepd... 

Monosubstituted acetylenic compounds can be oxidatively dimerized by air at room temperature in the presence of copper salts in a pyridine-methanol solution. This method has been applied to a wide variety of acetylenic compounds and gives high yields in disubstituted diacetylenic compounds (equation 264).590... 

Tsuji and coworkers reported that copper(I) chloride in the presence of pyridine, methanol and dioxygen promotes the stoichiometric oxidation of pyrocatechol to methyl muconate.606 Labeling lg02 studies have shown that only one atom of the dioxygen molecule is incorporated in the substrate, while the other one is transformed into water as in enzymic monooxygenases (equation 275)607 (and not as in dioxygenases, viz. pyrocatechase). This reaction has been shown by Rogic et al. to proceed via two steps (equation 276).580,58 ... 

This paper presents quantum mechanical studies of the, 5N and, 3C chemical shifts in both the N7-H and N9-H tautomeric forms of purine. Quantum mechanical calculations of the chemical shifts were used to assign the NMR resonances and the spatial orientation of the principal axes of the chemical shift tensors. Calculations in purine and in a pyridine-methanol complex model provide insights on the importance of the intermolecular interactions on the chemical shifts of the nucleic acid bases. 

It is apparent from the calculations in the model pyridine-methanol system, that various principal components of the chemical shift tensor are affected differently by the HB. Consequentely, the principal values perpendicular to the direction of the interaction will exhibit a greater effect than the shielding components along the direction of the interaction. This general argument is in agreement with the qualitative observations in purine. A full 3D study of the interaction in the pyridine-methanol complex is required to quantitatively interpret the results in purine. 

Figure 4 Dependence of the 15N principal values of the chemical shift in pyridine with the N-H distance for the pyridine-methanol complex. Note the different chemical shift scales for each shift component, SUj <%2, 3 and < so. The N-H distances are in A and the horizontal scales in the figure are the same for all the shift components.

The 15N chemical shift tensors in purine are similar to those in other nucleic acid bases for similar types of nitrogens. Comparison of the calculated values in purine for the isolated molecule and for the molecule with its nearest neighbors shows well defined trends, which could be rationalized using the results in the model pyridine-methanol complex. 

In the iodimetric titration procedure, the combustion gases are bubbled through a diluent solution containing pyridine, methanol, and water. This solution is titrated with a titrant containing iodine in a pyridine, methanol, and water solution. In automated systems, the titrant is delivered automatically from a calibrated burette syringe and the endpoint detected amperometrically. The method is empirical, and standard reference materials with sulfur percentages in the range of the samples to be analyzed should be used to calibrate the instrument before use. Alternative formulations for the diluent and titrant may be used in this method to the extent that they can be demonstrated to yield equivalent results. 

Other reactions show an even greater resemblance to those which occur in biological systems. A typical example is seen in the smooth oxidation of catechol by dioxygen in the presence of mixed pyridine/methanol solutions containing copper(i) chloride (Fig. 9-28). The cleavage products in this reaction are derived from an intermediate 1,2-quinone. 

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