Alcohols pyridine

NaBH4 is soluble in water, alcohols, pyridine, dioxane, dimethoxyethane, diglyme and triglyme. All these solvents, as well as aqueous tetrahydrofuran and aqueous dimethylformamide, have been used for reductions. The reductions go very slowly in di- and triglyme so these solvents are not suitable for preparative work. In some reductions in dry pyridine and dry dimethyl sulfoxide, reaction only takes place on aqueous work-up. This... 

Acyl chlorides are highly reactive acylating agents and react very rapidly with alcohols and other nucleophiles. Preparative procedures often call for use of pyridine as a catalyst. Pyridine catalysis involves initial formation of an acyl pyridinium ion, which then reacts with the alcohol. Pyridine is a better nucleophile than the neutral alcohol, but the acyl pyridinium ion reacts more rapidly with the alcohol than the acyl chloride.103... 

Cr en 2 (SCN) 2]SCN.a H 20, is produced from triethylenediamino-chromic thiocyanate, [Cr en3](SCN)3.H20, on heating it to 130° C., when it loses a molecule of ethylenediamine and a molecule of water. The mass is extracted -with water and allowed to crystallise. It crystallises in orange-yellow prisms which are soluble in alcohol, pyridine, and water, but a solution in the latter decomposes on heating. Chlorine transforms it into green tram-dichloro-salt.2 3... 

The complexes HgNi(NCS)4, HgNi(NCSe)4 and HgNi(NCS)2(NCSe)2 are supposed to contain six-coordinate nickel(II) in a polynuclear structure.1082 1089 All of the complexes with the general formula HgNi(NCX)4 behave as Lewis acids towards a number of bases such as alcohols, pyridine and substituted pyridines, PPh3, bipy, phen, DMSO, etc., giving in most cases polynuclear species.1084,1089... 

Only a few examples have been reported of the etherification of alcohols with resin-bound diarylmethyl alcohols (Entry 5, Table 3.30 Entry 5, Table 3.31 [564]). Diarylmethyl ethers do not seem to offer advantages over the more readily accessible trityl ethers, which are widely used as linkers for both phenols and aliphatic alcohols. Attachment of alcohols to trityl linkers is usually effected by treating trityl chloride resin or 2-chlorotrityl chloride resin with the alcohol in the presence of a base (phenols pyridine/THF, 50 °C [565] or DIPEA/DCM [566] aliphatic alcohols pyridine, 20-70 °C, 3 h-5 d [567-572] or collidine, Bu4NI, DCM, 20 °C, 65 h [81]). Aliphatic or aromatic alcohols can be attached as ethers to the same type of light-sensitive linker as used for carboxylic acids (Section 3.1.3). 

Chromium pentaphenyl chloroacetate trihydrate, (C6H5)5 Cr(0.C0.CH2Cl)2H.3H20, from monochloracetic acid and the chromium base, forms hygroscopic, intensely red plates, M.pt. 103° C. The anhydrous salt is also known. The products dissolve readily in alcohol, pyridine or ethyl acetate. 

Compound from m-NitrophenoL—The base and the phenol yield the product (C6H5)5Cr.0.C6H4.N02.H0.C6H4.N02, M.pt. 86° C., readily soluble in alcohol, pyridine or chloroform, less soluble in benzene or carbon disulphide, insoluble in ether or ligroin. 

Chromium tetraphenyl hydrogen oxanilate,1 (C6H6)4Cr.02C. C0.NH.C6H5.C6H5.NH.C0.C02H, from the pentaphenyl base and oxanilic acid, yields orange-red needles, M.pt. 1-11° C., very soluble in methyl alcohol, pyridine or chloroform, sparingly soluble in ethyl alcohol, insoluble in benzene. 

Compound from p-Bromophenol.—In this case the product has the structure (C6H5)4Cr.O.C6H4.Br.HO.CeH4.Br, and separates as glistening orange plates, M.pt. 121° C., soluble in alcohol, pyridine or ethyl acetate, less soluble in chloroform, sparingly soluble in benzene, ligroin, carbon disulphide, ether or water. 

Although Cr03 is soluble in some organic solvents, like tert-butyl alcohol, pyridine or acetic anhydride, its use in such solvents is limited, because of the tendency of the resulting solutions to explode.2,3 Nevertheless, acetone can safely be mixed with a solution of chromium trioxide in diluted aqueous sulfuric acid. This useful property prompted the development of the so-called Jones oxidation, in which a solution of chromium trioxide in diluted sulfuric acid is dropped on a solution of an organic compound in acetone. This reaction, first described by Jones,13 has become one of the most employed procedures for the oxidation of alcohols, and represents a seminal contribution that prompted the development of other chromium (VI) oxidants in organic synthesis. 

First, 1 2 metal complexes of (mainly mono-) azo dyes, without sulfonic or carboxylic acid groups, and trivalent metals (see Section 3.11). The metals are preferably chromium and cobalt nickel, manganese, iron, or aluminum are of lesser importance. Diazo components are mainly chloro- and nitroaminophenols or amino-phenol sulfonamides coupling components are (3-naphthol, resorcinol, and 1-phe-nyl-3-methyl-5-pyrazolone. Formation of a complex from an azo dye and a metal salt generally takes place in the presence of organic solvents, such as alcohols, pyridine, or formamide. An example is C.I. Solvent Red 8, 12715 [33270-70-1] (1). 

Isoamyl alcohol pyridine water (2 1 2). 6. Two dimensional chromatography consists of ... 

Solvent manufacturer Honeywell Burdick Jackson [39] defines solvents as miscible if the two components can be mixed together in all proportions without forming two separate phases. A solvent miscibility chart (Figure 2.12) is a useful aid for determining which solvent pairs are immiscible and would therefore be potential candidates for use in LLE. More solvent combinations are miscible than immiscible, and more solvents are immiscible with water than with any other solvent. Solvents miscible with water in all proportions include acetone, acetonitrile, dimethyl acetamide, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, ethyl alcohol, glyme, isopropyl alcohol, methanol, 2-methoxyethanol, /V-methyI pyitoI idone. n-propyl alcohol, pyridine, tetrahydrofuran, and trifluoroacetic acid [40]. 

Free radical mechanisms of the photolytic decomposition of R MCOR (M = Ge, Sn) were considered in a number of earlier fundamental studies30,31. The nature of the resulting reaction products identified in nonpolar (alkanes, benzene, either in the presence or in the absence of a radical trap) or polar (alcohols, pyridine) media has allowed the proposal of a generalized reaction mechanism of the photolysis of R GeCOR compounds (Scheme 2). 

Pyridine complexes of Rh111 have played a central role in the still poorly understood area of catalyzed substitutions at Rh111 centers. Delepine first noted that the consecutive substitution of [RhCl6]3 by pyridine leads to the neutral, and insoluble, [Rhpy3Cl3], but that if the aqueous solvent includes some alcohol, pyridine substitution continues and rans,-[Rhpy4Cl2]+ is the final product (equation 155).784 Delepine showed that primary alcohols all had comparable effects on the rate of formation of [Rhpy4Cl2]+, and that secondary alcohols were less active than primary alcohols.785 Tertiary alcohols proved to be totally inactive, as are ether, dioxane or acetone. Poulenc had also reported that ethanol catalyzed substitutions at Rhiri centers.793... 

Separations of various anions Using a solvent mixture composed of n-butyl alcohol, pyridine, and 1-5m ammonia solution in the proportions of 2 1 2, the following Rf values are obtained for the sodium or potassium salts chloride, 0-24 bromide, 0-36, iodide, 0-47 chlorate, 042, bromate, 0-25, iodate, 0-09 nitrite, 0-25 nitrate, 0-40 arsenite, 019 arsenate, 0 05 phosphate, 0-04 and thiocyanate, 0 56. The positions of the anions may be detected by spraying with ammoniacal silver nitrate potassium iodide and hydrochloric acid are particularly effective for chlorates, bromates, and iodates. The RF values provide the basis for the separation of a number of mixtures of anions, e.g. chloride and iodide, bromide or iodide and nitrate. 

Solubility whereas monosaccharides are very soluble in water and in polar solvents such as alcohols, pyridine and dimethylsulfoxide, solubility decreases when molecular weight increases thus some polysaccharides are totally insoluble. Formation of some polysaccharides in wines can produce defects (e.g. dextrans appearing in wines cause ropiness). 

Properties I Extracted rna pie sawdust 2 ( ) Chlorine and alcohol-Pyridine 3 2) Calcium hypochlorite solution Percent of original in (3)... 

In later work. Van Beckum and RitteP found that 3% ethanolamine in 95 % ethanol is more effective than alcohol-pyridine for the extraction of chlorolignin. An outline of the method follows. 

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