1.3.5- Tris benzene acetate

Mono-, di-, and tri-saccharide acetates were easily separated, using benzene-ethanol developer, into groups whose composition reflected the influence of molecular weight (see Fig. 12). The influence of the position of (see Fig. 13), - and the loss of polarity of, a functional group (see Fig. 14) on the adsorbability of acetates was interesting. Transformation of the carbo.xyl group of penta-O-acetyl-D-gluconic acid to certain nitro-... 

When a group separation is attempted on silicic acid, a 25-fold excess of adsorbent is used, and four fractions are collected (1) benzene 10 ml/g silicic acid, (2) benzene-acetic acid, 99 1, 30 ml/g silicic acid, (3) benzene-acetic acid, 3 1,40ml/g silicic acid, and (4) chloroform-methanol, 1 1,10 ml/g silicic acid. Fatty acids and sterols appear in the first two fractions where also unsubstituted cholanoic acid will be eluted. The third fraction contains mainly mono- and disubstituted bile acids and the last one the bulk of tri-substituted cholanoic acids (18). Silicic acid is sometimes very efficient for the separation of protected bile acids. Thus Wootton (71) obtained a partial separation of the methyl ester diacetates of deoxycholic and chenodeoxy-cholic acids on silica gel (Davison 923, Davison Chemical Corp., Baltimore). 

If this electrostatic treatment of the substituent effect of poles is sound, the effect of a pole upon the Gibbs function of activation at a particular position should be inversely proportional to the effective dielectric constant, and the longer the methylene chain the more closely should the effective dielectric constant approach the dielectric constant of the medium. Surprisingly, competitive nitrations of phenpropyl trimethyl ammonium perchlorate and benzene in acetic anhydride and tri-fluoroacetic acid showed the relative rate not to decrease markedly with the dielectric constant of the solvent. It was suggested that the expected decrease in reactivity of the cation was obscured by the faster nitration of ion pairs. 

Tris-(hydroxymethyl)nitromethane [2-(hydroxymethyl)-2-nitro-l,3-propanediol] [126-11-4] M 151.1, m 174-175°(dec, tech grade), 214°(pure). Crystd from CHCl3/ethyl acetate or ethyl acetate/ benzene. It is an acid and a O.IM sol in H2O has pH 4.5. IRRITANT. 

A cold (0°) solution of 15 g (0.039 mole) of cholest-4-en-3-one, mp 79-80°, in 200 ml of ether-benzene (8 1) is added dropwise to 0.05 mole of lithium tri-t-butoxyaluminum hydride in ether-diglyme at —40° to —50°. The mixture is allowed to stand overnight at 0° and then hydrolyzed by treatment with ice, 5 N sodium hydroxide and Rochelle salt. Evaporation of the washed and dried ether extracts and crystallization of the residue from ethyl acetate affords 13 g (87 % yield) of nearly pure cholest-4-en-3j9-ol, mp 126-129°. One recrystallization from the same solvent gives the pure product as large needles mp 131-132°, [a]o 46° reported mp 132° [a]c, 44° (benzene). 

A Solid. —If the substance is a solid, evainine a few particles on a slide under the microscope, 01, better still, recrystallise a little if possible and notice if the crystals appear similar in shape. If it is a mixture, try to separate the constituents by making a few trials with different solvents, watei, alcohol, ether, benzene, jjetioleum spirit, ethyl acetate, acetic acid, etc. 

A kinetic isotope effect, kH/kD = 1.4, has been observed in the bromination of 3-bromo-l,2,4,5-tetramethylbenzene and its 6-deuterated isomer by bromine in nitromethane at 30 °C, and this has been attributed to steric hindrance to the electrophile causing kLx to become significant relative to k 2 (see p. 8)268. A more extensive subsequent investigation304 of the isotope effects obtained for reaction in acetic acid and in nitromethane (in parentheses) revealed the following values mesitylene, 1.1 pentamethylbenzene 1.2 3-methoxy-1,2,4,5-tetramethyl-benzene 1.5 5-t-butyl-1,2,3-trimethylbenzene 1.6 (2.7) 3-bromo-1,2,4,5-tetra-methylbenzene 1.4 and for 1,3,5-tri-f-butylbenzene in acetic acid-dioxan, with silver ion catalyst, kH/kD = 3.6. All of these isotope effects are obtained with hindered compounds, and the larger the steric hindrance, the greater the isotope... 

Subsequently, rate coefficients were determined for the zinc chloride-catalysed bromination of benzene, toluene, i-propyl-benzene, r-butylbenzene, xylenes, p-di-f-butylbenzene, mesitylene, 1,2,4-trimethyl-, sym-triethyl-, sym-tri-f-butyl-, 1,2,3,5-and 1,2,4,5-tetramethyl- and pentamethylbenzenes, all at 25.4 °C and in acetic acid, and it was shown that the reaction was inhibited by HBr.ZnCl2 which accumulates during the bromination and was considered to cause the first step of the reaction (formation of ArHBr2) to reverse320. The second-order coefficients for bromination of o-xylene at 25.0 °C were shown to be inversely dependent upon the hydrogen bromide concentration and the reversal of equilibrium (155)... 

In weaker acid systems, other reactions involving the triplet state supervene to the exclusion of dimerization. Photolysis of 85 in 3-3% sulfuric acid, 96-5% acetic acid, and 0-2% water gave as products tri-phenylmethane (93), 9-phenylfluorene (94), 6is-9-phenylfluorenyl peroxide (95) and benzophenone (96). When benzene was present, tetra-phenylmethane (97) was also formed in addition to the other products. When the triphenylmethyl cation is irradiated in 3-3% H2SO4, 80 1% HOAc, 16-4% toluene, and 0-2% H2O, the products observed were... 

A cage-like complex results from the tris(imidazol-l-ylmethyl)benzene ligand in the presence of zinc acetate, [Zn3L2(OAc)6], and exhibits inclusion properties to neutral guest molecules in aqueous solution.134... 

These acid-catalyzed C-glycosylations were successfully extended to the D-ribofuranose series by Sorm and coworkers,148 who utilized the reaction in the first reported synthesis of showdomycin. Thus, treatment of 2,3,5-tri-0-benzoyl-/3-D-ribofuranosyl bromide (81) with 1,2,5-trimethoxybenzene in the presence of zinc oxide gave 2,4,6-trimethoxy-l-(2,3,5-tri-0-benzoyl-/3-D-ribofuranosyl)benzene (196). Ozonolysis of the corresponding acetate derivative, followed by esterification, gave the highly functionalized C-/3-I>ribofuranosyl derivative (197), which was used as a key intermediate in the synthesis of showdomycin (see Section III,l,b). 

Cyclic 1,3-diketones have been converted into / -halogeno-ketones (118) by tri-phenylphosphine dihalides in benzene or acetonitrile,100 although this paper adds little to previous work101 in this field. The reactions of phosphorus pentachloride with acetals have been extended to mixed acetals, such as (119).102 Only one product... 

The catalysis by a protected nucleoside of the aminolysis by butylamine of / -nitrophenyl acetate in benzene (Scheme 3) has been reported. Interestingly, only 2, y, 5 -<9-tris(t-butyldimethylsilyl)cytidine showed any marked catalytic effect, the adenosine, guanosine and uridine analogues behaving merely as weak general base... 

AI3-00040, see Cyclohexanol AI3-00041, see Cyclohexanone AI3-00045, see Diacetone alcohol AI3-00046, see Isophorone AI3-00050, see 1,4-Dichlorobenzene AI3-00052, see Trichloroethylene AI3-00053, see 1,2-Dichlorobenzene AI3-00054, see Acrylonitrile AI3-00072, see Hydroquinone AI3-00075, see p-Chloro-rrr-cresol AI3-00078, see 2,4-Dichlorophenol AI3-00085, see 1-Naphthylamine AI3-00100, see Nitroethane AI3-00105, see Anthracene AI3-00109, see 2-Nitropropane AI3-00111, see Nitromethane AI3-00118, see ferf-Butylbenzene AI3-00119, see Butylbenzene AI3-00121, see sec-Butylbenzene AI3-00124, see 4-Aminobiphenyl AI3-00128, see Acenaphthene AI3-00134, see Pentachlorophenol AI3-00137, see 2-Methylphenol AI3-00140, see Benzidine AI3-00142, see 2,4,6-Trichlorophenol AI3-00150, see 4-Methylphenol AI3-00154, see 4,6-Dinitro-o-cresol AI3-00262, see Dimethyl phthalate AI3-00278, see Naphthalene AI3-00283, see Di-rj-butyl phthalate AI3-00327, see Acetonitrile AI3-00329, see Diethyl phthalate AI3-00399, see Tributyl phosphate AI3-00404, see Ethyl acetate AI3-00405, see 1-Butanol AI3-00406, see Butyl acetate AI3-00407, see Ethyl formate AI3-00408, see Methyl formate AI3-00409, see Methanol AI3-00520, see Tri-ocresyl phosphate AI3-00576, see Isoamyl acetate AI3-00633, see Hexachloroethane AI3-00635, see 4-Nitrobiphenyl AI3-00698, see IV-Nitrosodiphenylamine AI3-00710, see p-Phenylenediamine AI3-00749, see Phenyl ether AI3-00790, see Phenanthrene AI3-00808, see Benzene AI3-00867, see Chrysene AI3-00987, see Thiram AI3-01021, see 4-Chlorophenyl phenyl ether AI3-01055, see 1.4-Dioxane AI3-01171, see Furfuryl alcohol AI3-01229, see 4-Methyl-2-pentanone AI3-01230, see 2-Heptanone AI3-01231, see Morpholine AI3-01236, see 2-Ethoxyethanol AI3-01238, see Acetone AI3-01239, see Nitrobenzene AI3-01240, see I idine AI3-01256, see Decahydronaphthalene AI3-01288, see ferf-Butyl alcohol AI3-01445, see Bis(2-chloroethoxy)methane AI3-01501, see 2,4-Toluene diisocyanate AI3-01506, see p,p -DDT AI3-01535, see 2,4-Dinitrophenol AI3-01537, see 2-Chloronaphthalene... 

We then designed model studies by adsorbing cinchonidine from CCU solution onto a polycrystalline platinum disk, and then rinsing the platinum surface with a solvent. The fate of the adsorbed cinchonidine was monitored by reflection-absorption infrared spectroscopy (RAIRS) that probes the adsorbed cinchonidine on the surface. By trying 54 different solvents, we are able to identify two broad trends (Figure 17) [66]. For the first trend, the cinchonidine initially adsorbed at the CCR-Pt interface is not easily removed by the second solvent such as cyclohexane, n-pentane, n-hexane, carbon tetrachloride, carbon disulfide, toluene, benzene, ethyl ether, chlorobenzene, and formamide. For the second trend, the initially established adsorption-desorption equilibrium at the CCR-Pt interface is obviously perturbed by flushing the system with another solvent such as dichloromethane, ethyl acetate, methanol, ethanol, and acetic acid. These trends can already explain the above-mentioned observations made by catalysis researchers, in the sense that the perturbation of initially established adsorption-desorption equilibrium is related to the nature of the solvent. 

The solvents most commonly employed are water, ethyl and methyl alcohol, ether, benzene, petroleum ether, acetone, glacial acetic acid also two or three solvents may be mixed to get the desired effect as described later. If you still cannot dissolve the compound, try some of these chloroform, carbon disulfide, carbon tetrachloride, ethyl acetate, pyridine, hydrochloric acid, sulfuric acid (acids are usually diluted first), nitrobenzene, aniline, phenol, dioxan, ethylene dichloride, di, tri, tetrachloroethylene, tetrachloroethane, dichloroethyl ether, cyclohexane, cyclohexanol, tetralin, decalin, triacetin, ethylene glycol and its esters and ethers, butyl alcohol, diacetone alcohol, ethyl lactate, isopropyl ether, etc. 

Treat the mixture with decolorizing carbon and then ev orate in vacuo to 10 ml. Pour onto a mixture of 30 ml of chloroform, ice, and 10 g of sodium bicarbonate. Separate the chloroform layer, and extract the aqueous phase with three 10 ml portions of chloroform. The combined chloroforms are dried, evaporated to dryness in vacuo, and the product is crystallized from benzene to give g of product that melts at 159-160°. You may purify more by recrystallizing from ethyl acetate. This is not very much product. As with the procedure 4 steps back, you will have to perform this step over and over. If you try to double or triple the amounts given, you may get more product, but you will hurt the yield. 

As Schaffer has found 2.4.6-triphenyl-X -phosphorin 22 and other 2.4.6-tri-substituted X -phosphorins react smoothly with aryl diazonium salts in benzene. Nitrogen develops and the aryl residue bonds with the phosphorus. In presence of alcohols as nucleophiles, l-alkoxy-l-aryl-2.4.6-triphenyl-X -phosphorins 100 can be isolated. The aryl diazonium-tetrafluoroborate without any nucleophile in DMOE yields l-aiyl-l-fluoro-2.4.6-triphenyl-X -phosphorin 70i. As with other oxidants like halogen or mercury-Il-acetate, we suppose that in the first step triphenyl-X -phosphorin radical cation is formed. This could be shown by ESR spectroscopy. The next step may be a radical-radical addition to the X -phosphorin cation or a nucleophileradical addition respectively ... 

Treatment of 15 with l,5-diazabicyclo[5.4.0]undec-5-ene (DBU) in benzene resulted in /3-elimination, but under these conditions, the liberated 2,3,4,6-tetra-O-methyl-D-glucose was further degraded, probably with formation of 3-deoxy-2,4,6-tri-0-methyl-D-erc/fhro-hex-2-enopyranose. In order to prevent this degradation, the reaction of 15 with DBU was carried out in the presence of acetic anhydride. The reaction mixture gave, after chromatography on silica gel, methyl (methyl 4-deoxy-2,3-di-0-methyl-a-L-threo-hex-4-enopyranosid)uron-ate (65) and a mixture of the 1-acetates of 2,3,4,6-tetra-O-methyl-a- and -/3-D-glucose (66). 

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