Tris methanol

Desperate, you try methanol, one of the most polar solvents. It is really held strongly to the adsorbant. So it comes along and kicks the living daylights out of just about all the molecules in the mixture. After all, the methyl alcohol is more polar, so it can move right along and displace the other molecules. And it does. So, when you evaporate the methanol and look, all the mixture has moved with the methanol, so you get one spot that moved, right with the solvent front. 

The mono-, di-, and tri-phosphorylates of d4T were analysed by ion-pair LC-MS after lysis of the PBMC cell in Tris/methanol and centrifugation [50]. The supernatant was injected into the LC system with a 150x2.1-mm-ID Cjg column (5 pm) and a mobile-phase gradient of 70 to 35% solvent A (10 mmol/1 DMHA and 3 mmol/1 ammonium formate adjusted at pH 11.5) in solvent B (50% acetonitrile in 20 mmol/1 DMHA and 6 mmol/1 ammonium formate). Negative-ion ESI-MS was performed in SRM mode. The method enabled the direct measurement of the chain terminator ratio (d4T-triphosphate/deoxythymidine-triphosphate). Subsequently, the same group [51] reported modifications of this method, including simplifications of the sample pretreatment, replacement of the LC column for another type, and reduction of the column inner diameter from 2 mm ID to 0.32 mm ID. This improved method was applied to the determination of the phosphorylates of d4T, 3TC, and ddl. The sample throughput is 200 samples per week. The determination of intracellular AZT-triphosphate in PBMC [52], and the validation of the method for the determination of the ddl and d4T triphosphates was reported separately [53]. 

Isolate Compoimd 2 and dry it in an oven at about 110°C. Purify it by crystallization (see Technique 11, Section 11.5 for instructions on how to determine an appropriate solvent). You should try methanol and 95% ethanol. After determining the best solvent, purify the compound by crystallization and identify the purified solid using some or all of the techniques given in the next section, "Identification of Compounds."... 

It will be a little tricky but one can also try to purify by freezing I The sassafras oil is thrown into the freezer to chill. Safrole itself freezes at -14°C so anything that starts to freeze prior to that can be cold filtered in a prechilled vacuum filtration setup. The filtrate goes back in the freezer until -14°C is reached and the mother lode of safrole freezes up. This again is filtered cold but this time the frozen mass of safrole crystals are washed with some ice cold methanol or ethanol (preferably at -14°C) to wash away the unfrozen high-boiling constituents. 

The advantage of this definition is that it does not depend on measuting the tangent of the response curve, although the variation ia the value of the blending octane number is greater. Typically, BONs are measured at an 80/20 mixture. This technique is also usehil when trying to measure the octane of a compound such as butane or methanol that is difficult or impossible to measure ia its pure state. 

The reactions of trialkylboranes with bromine and iodine are gready accelerated by bases. The use of sodium methoxide in methanol gives good yields of the corresponding alkyl bromides or iodides. AH three primary alkyl groups are utilized in the bromination reaction and only two in the iodination reaction. Secondary groups are less reactive and the yields are lower. Both Br and I reactions proceed with predominant inversion of configuration thus, for example, tri( X(9-2-norbomyl)borane yields >75% endo product (237,238). In contrast, the dark reaction of bromine with tri( X(9-2-norbomyl)borane yields cleanly X(9-2-norbomyl bromide (239). Consequentiy, the dark bromination complements the base-induced bromination. 

These compounds are highly soluble in water. AMP, AMPD, AEPD, and DMAMP are completely miscible in water at 20 °C the solubihty of AB is 250 g/100 mL H2O at 20°C. They are generally very soluble in alcohols, slightly soluble in aromatic hydrocarbons, and nearly insoluble in aliphatic hydrocarbons tris(hydroxymethy1)aminomethane [77-86-1] is appreciably soluble only in water (80 g/100 mL at 20°C) and methanol. 

The principal solvents that have been used are alcohols such as ethanol, methanol, and propanol, and organic acids such as formic or acetic acid, but other solvents iaclude esters, ethers, phenols, cresols, and some amines. Even solvents such as CO2 and NH in the supercritical fluid state have been tried as solvents. 

Note The pre- and post-treatment of the chromatograms with the basic tri-ethylamine solution, which can be replaced by an alcoholic solution of sodium hydroxide [1,4] or a phosphate buffer solution pH = 8.0 (c = 0.2 mol/1) [5], serves to stabilize the fluorescence of the amino derivatives [2]. A final spraying with methanolic hydrochloric acid (chci = 5 mol/1) or 70% perchloric acid renders the detection reaction highly specific for histamine [4] and for catecholamines and indolamines [5]. 

Tris-methylthio-s-triazine undergoes similar displacement with methanolic methoxide. Its methylthio groups are substituted with sodium sulfide and with ammonia. Methylthio and carboxymethylthio substituents are readily hydrolyzed by dilute acid. ... 

The reaction of 2, 3, 5 -tri-0-acetylguanosine (32a) with diazomethane in methanol-acetone mixture may also be mentioned here. 

It was found that the reaction of the lactone glycosides (5/ )- and (5S)-5-methoxy-5-(2,3,5-tris-(9-benzoyl-/3-D-ribofuranosyl)-2(5//)-furanone270and271 with hydrazine hydrate in methanol gave two products the pyridazinone 272 and a mixture of diastereomeric A -aminopyrrolinones 273, which could not be separated, in yields of 26 and 71%, respectively (Scheme 70) (87JOC4521). 

The following method is described in U.S. Patent 2,430,891. To a solution of 10 parts of tris-p-methoxyphenyl ethylene in 35 to 40 parts of carbon tetrachloride Is added a solution of 2.0 parts of chlorine in 50 parts of carbon tetrachloride, with stirring, and over a period of Vj hour. The carbon tetrachloride is then removed by distillation on a steam bath and the residual oil is recrystallized from 250 to 400 parts of methanol, decolorizing with charcoal or the like if necessary. Tris-p-methoxyphenyl chloroethylene is obtained in a yield of 65 to 75%. It melts at 113° to 114°C. 

A small amount of undissolved material collected on the filter and it was washed with chloroform. The chloroform solution (filtrate plus washings) was washed three times with ice-water, twice with ice-cold 3N sulfuric acid, twice with ice-cold saturated aqueous sodium bicarbonate solution, twice with ice-water, and then dried over anhydrous sodium sulfate. The chloroform was removed under reduced pressure at a bath temperature of about 40°C, leaving a yellow, somewhat gummy residue. This yellow residue was dissolved in absolute methanol which was then evaporated at reduced pressure at about 40°C, and the residue was then held for 2 hours at 0.5 to 2.0 mm pressure and a bath temperature of about 50°C. There was thus obtained 1.69 g of T(2,3,5-tri-0-acetyl-(3-D-arabinofuranosyl)-4-thiouracil. 

B) Preparation of 1-0-D-Arabinofuranosylcytosine In a glass liner, a mixture of 1.16 g (3.0 mmol) of 1-(2,3,5-tri-0-acetyl-(3-D-arabinofuranosyl)-4-thiouracil prepared in (A) and about 60 ml of absolute methanol which had been saturated with anhydrous ammonia at 0°C was heated in a steel bomb at 98° to 105°C for 35 hours. After cooling to about 25°C and venting the bomb, the dark solution was filtered into a round-bottom flask. The methanol and excess ammonia were then removed under reduced pressure at about 25°C. The residual syrup was dissolved in absolute methanol, and the methanol was removed under reduced pressure at a bath temperature of about 40°C. This procedure of dissolving in absolute methanol and removing the solvent was repeated, and the residue was held under reduced pressure at a bath temperature of 45°C for 12 hours. 

Dissolution and the crystallization occurred and the precipitate was recovered by filtration and was washed and dried to obtain 16 grams of crude base having a melting point of 179° to 180°C. The crude base was crystallized from methanol with treatment with charcoal to obtain 11.95 grams of 4-[ortho-(2, 3 -dihydroxypropyloxycarbonyl)-phenyl]-amino-8-tri-fluoromethylquinoline with a melting point of 179° to 180°C. The product is soluble in ether, chloroform and methylene chloride and insoluble in water. 

A precursor in the synthesis of a promising calcium sensitizing agent from E. Merck [33], a chiral thiadiazin-2-one EMD 53986, 3,6-Dihydro-5-[l,2,3,4-tetrahy-dro-6-quinolyl]-6-methyl-2H-l,3,4-thiadiazin-2-one [26]. The study was performed using Celluspher , a CSP prepared from cellulose tri(p-methylbenzoate) according to a patent from Ciba-Geigy [34]. The spherical particles had a mean particle diameter of 20 3 pm and the mobile phase was pure methanol. 

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