Methanol five solutes

However, when 78% of the starting ketone had reacted, only 22% of low molecular weight products was isolated. In 90% methanol-water solution under the same conditions five products were formed ... 

Erk [20] described a spectrophotometric method for the simultaneous determination of metronidazole and miconazole nitrate in ovules. Five capsules were melted together in a steam bath, the product was cooled and weighed, and the equivalent of one capsule was dissolved to 100 mL in methanol this solution was then diluted 500-fold with methanol. In the first method, the two drugs were determined from their measure d%/dk values at 328.6 and 230.8 nm, respectively, in the first derivative spectrum. The calibration graphs were linear for 6.2—17.5 pg/mL of metronidazole and 0.7—13.5 pg/mL of miconazole nitrate. In the second (absorbance ratio) method, the absorbance was measured at 310.4 nm for metronidazole, at 272 nm for miconazole nitrate and at 280.6 nm (isoabsorptive point). The calibration graphs were linear over the same ranges as in the first method. 

A procedure is presented for correlating the effect of non-volatile salts on the vapor-liquid equilibrium properties of binary solvents. The procedure is based on estimating the influence of salt concentration on the infinite dilution activity coefficients of both components in a pseudo-binary solution. The procedure is tested on experimental data for five different salts in methanol-water solutions. With this technique and Wilson parameters determined from the infinite dilution activity coefficients, precise estimates of bubble point temperatures and vapor phase compositions may be obtained over a range of salt and solvent compositions. 

Data have been presented for five salts in methanol-water solutions, which indicate clearly the influence of salt concentration on the observed salt effects and the Wilson parameters. 

There appears to be more reason to record extra chromatograms if the result of the optimization process is not satisfactory. For instance, if the chromatogram of figure 5.33g has been obtained and if it can safely be assumed that there are no more than five solutes present in the sample, then there is no reason to record an additional chromatogram in the middle (x = 0.5) of the large unsearched area corresponding to the acetonitrile-methanol-water system. 

Five grams of the crude 4 0 isomer obtained as described above is dissolved in 500 mL of chloroform and loaded onto an 8 X 30 cm column of 60-200 mesh silica prepared as a slurry in chloroform. After it is loaded, the column is eluted with 1 L of chloroform and then with 1 1 benzene/diethyl ether (about 2.5 L) until the eluates are essentially colorless. The pure 4 0 isomer is then eluted using acetone/diethyl ether (1 1) and the solution is subsequently taken to dryness at ambient temperature using a rotary evaporator. The residue is dissolved in chloroform, and after the addition of methanol, the solution is concentrated slowly to 75 mL at room temperature using a rotary evaporator. The resulting purple crystals are filtered, washed with methanol, and dried in air at room temperature. Yield 4.0-4.5 g. Again, the separation may be followed by tic analysis of the eluate. The checkers found that the 4 0 isomer needed to be chromatographed a third time to purify it completely. 

General Procedure for Cl Ion Loss Experiments. Methanolic PVP solutions (1.86 mgs/50 mis CHjOH) were prepared so that a 10pl aliquot applied to a vertically mounted glassy carbon disk delivered 5 x 10-8 moles of pyridyl sites per square cm of electrode area. The solution was allowed to air-dry, forming a visible film on the electrode surface. The film-covered electrode was then rinsed in stirring methanol for five minutes to swell the polymer and re-dried. 

Thirty five grams of alumina is made into a slurry with petroleum ether and transferred to a chromatographic column. Twenty five mL of azobenzene solution is placed in an evaporating dish and irradiated for 30 minutes with uv radiation (the more intense the better). The sample then is added to the column. The tram isomer is eluted with petroleum ether, and the cis isomer is eluted with petroleum ether + 1% methanol. The solutions are collected, the solvent is evaporated, and the melting points are obtained to establish purity. 

Rose and Wilkinson, by treatment of the methanolic blue solutions with various cations, have trapped out stable solids of composition M[Ru5Cl,2] (M = Fe(bipy)3 , Ru(bipy)3 , [C6H4(CH2PPh3)2] " and proposed structure (359). The ESR spectra of these materials are essentially identical to those of the blue solutions in various solvents, so it is reasonable to assume that the ion present in the solids is also present in the blue solutions. However, the ESR spectrum and magnetic properties of (359) =1.3 BM per five ruthenium atoms) are not consistent with what... 

A solution of 24.6 g of o-allyl-epoxypropoxybenzene dissolved in 250 ml of absolute ethanol saturated with ammonia was placed in an autoclave and heated on a steam-bath for 2 hours. The alcohol was then removed by distillation and the residue was redissolved in a mixture of methanol and ethylacetate. Hydrogen chloride gas was introduced into the solution. The hydrochloride salt was then precipitated by the addition of ether to yield 11.4 g of product. Five grams of the amine-hydrochloride thus formed were dissolved in 50 ml of methanol and 9 ml of acetone. The resulting solution was cooled to about 0°C. At this temperature 5 g of sodium borohydride were added over a period of 1 hour. Another 2.2 ml of acetone and O.B g of sodium borohydride were added and the solution was kept at room temperature for 1 hour, after which 150 ml of water were added to the solution. The solution was then extracted with three 100-ml portions of ether which were combined, dried over potassium carbonate, and evaporated. The free base was then recrystallized from petrol ether (boiling range 40°-60°C) to yield 2.7 g of material having a melting point of 57°C. 

Five hundred milligrams of (dl)-reg.-Tphenvl-2-dichloroacetamidopropane-1,3-diol is added to a solution consisting of 1 cc of pyridine and 1 cc of acetic anhydride and the resulting reaction mixture heated at 100°C for % hour. The reaction mixture is evaporated to dryness under reduced pressure and the residue taken up in and crystallized from methanol. Recrystallization from methanol produces the pure diacetate of (dl)-reg.-1-phenyl-2-dichloro-acetamidopropane-1,3-diol (MP 94°C). 

In about 250 cc of liquid ammonia (cooled with dry ice and acetone) are dissolved about 7.5 g of potassium and into the solution acetylene is passed until the blue color has disappeared (about 3 hours). Then slowly a solution or suspension of 3 g of estrone in 150 cc of benzene and 50 cc of ether is added. The freezing mixture is removed, the whole allowed to stand for about 2 hours and the solution further stirred overnight. Thereupon the reaction solution is treated with ice and water, acidified with sulfuric acid to an acid reaction to Congo red and the solution extracted five times with ether. The combined ether extracts are washed twice with water, once with 5% sodium carbonate solution and again with water until the washing water is neutral. Then the ether is evaporated, the residue dissolved in a little methanol and diluted with water. The separated product is recrystallized from aqueous methanol. The yield amounts to 2.77 g. The 17-ethiny I-estradiol-3,17 thus obtained melts at 142°C to 144°C . 

Methyl 2-deoxy-39496-tri-0-p-nitrobenzoyl-p-T>- yxo-hexoside. A solution of 370 mg. of 2-deoxy-3,4,6-tri-0-p-nitrobenzoyl- -D-Zyxo-hexosyl bromide (5) in 15 ml. of dry dichloromethane is added to a stirred suspension of 500 mg. of silver carbonate in 100 ml. of absolute methanol. The mixture is stirred for 20 hours and filtered the silver salts are washed several times with warm dichloromethane. The combined filtrate and washings are evaporated to dryness under diminished pressure, and the residue is recrystallized five times from ether-dichloromethane, giving 61% of pure product, having m.p. 173°-174°C. and [ ]D + 36° in chloroform. 

Considerably less is known about the chemistry of palladium and platinum 1,1-dithio complexes. Of late, there has been only one report that dealt with the synthesis of a large number of palladium dithiocar-bamates 392). Twenty-five yellow palladium dithiocarbamate complexes were obtained by reaction of PdCla with NaR2dtc in methanol solution. Several other reports have appeared in which a few dithiocarbamate complexes of palladium were synthesized. Thus, the novel [Pd (OH)2dtc 2], which is soluble in water, was isolated 393). The synthesis of optically active palladium(II) complexes of AT-alkyl-a-phen-ethyldithiocarbamates, similar to (XXIV), via the reaction between the optically active amine, CS2, and PdCl2, has been described. From ORD and CD spectra, it has been established that the vicinal contribution of a remote, asymmetric carbon center could give rise to optical activity of the d—d transitions of palladium 394). Carbon disulfide has been shown to insert into the Pt-F bond of [PtF(PPh3)3]HF2, and X-ray studies indicated the structure (XXIX). 

A peptoid pentamer of five poro-substituted (S)-N-(l-phenylethyl)glycine monomers, which exhibits the characteristic a-helix-like CD spectrum described above, was further analyzed by 2D-NMR [42]. Although this pentamer has a dynamic structure and adopts a family of conformations in methanol solution, 50-60% of the population exists as a right-handed helical conformer, containing all cis-amide bonds (in agreement with modeling studies [3]), with about three residues per turn and a pitch of 6 A. Minor families of conformational isomers arise from cis/trans-amide bond isomerization. Since many peptoid sequences with chiral aromatic side chains share similar CD characteristics with this helical pentamer, the type of CD spectrum described above can be considered to be indicative of the formation of this class of peptoid helix in general. 

General procedures for the synthesis of ligands and metal complexes are shown in Scheme 1. For file synthesis of 2a acenaphthenequinone (0.38 g, 2.1 mmol) and a,a-bis(4-amino-3,5-dimethylphenyl)-toluene(Kccess) were dissolved in 50 mL of CH3OH in a round-bottom flask. Five drops of formic acid were added, and the sealed solution was stirred at 50 C overnight. After filtration, the red solid was washed with hot methanol and dried to give 1.2 g of red powder in 50 % yield. 

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