Acetic acid mixture

Acetylation. Boil i g. of salicylic acid with 4 ml. of an acetic anhydride-acetic acid mixture (equal volumes) under reflux for 10 minutes. Pour into water. Filter off the aspirin (p. 111), wash with water and recrystallise from aqueous acetic acid (1 1) m.p. l36 ... 

Acetylation. Place 1 ml. of the substance (or, if solid, i g. of the powdered amine) in a small flask fitted with a reflux condenser (or in a test-tube fitted with a cold-finger, as in Fig. 35, p. 62), add 5 ml. of an acetic anhydride-acetic acid mixture (equal volumes) and reflux... 

The GBR resin works well for nonionic and certain ionic polymers such as various native and derivatized starches, including sodium carboxymethylcel-lulose, methylcellulose, dextrans, carrageenans, hydroxypropyl methylcellu-lose, cellulose sulfate, and pullulans. GBR columns can be used in virtually any solvent or mixture of solvents from hexane to 1 M NaOH as long as they are miscible. Using sulfonated PDVB gels, mixtures of methanol and 0.1 M Na acetate will run many polar ionic-type polymers such as poly-2-acrylamido-2-methyl-l-propanesulfonic acid, polystyrene sulfonic acids, and poly aniline/ polystyrene sulfonic acid. Sulfonated columns can also be used with water glacial acetic acid mixtures, typically 90/10 (v/v). Polyacrylic acids run well on sulfonated gels in 0.2 M NaAc, pH 7.75. 

The azlactones are first hydrolyzed with alkali to the A-benzoylamino acid and thence to 32 using an HBr-acetic acid mixture. 

The solubility of the resulting product may dictate the choice of solvent. Reductive alkylation of norepinephrine with a series of keto acids proceeded smoothly over platinum oxide in methanol-acetic acid mixtures. However, when n = 4 or 5, the product tended to precipitate from solution, making catalyst separation difficult. The problem was circumvented by using glacial acetic acid as solvent 38). 

After addition of a few milliliters at 15°C, the thick slurry thins slowly and the remainder of the sulfuric-glacial acetic acid mixture was added at 0° to 2°C. A total of about 2 hours was required for the addition. After addition, stirring was continued for 15 minutes. Then dropwise, over an hour, a solution of 178 g (1.3 mols) of dl-camphene in 50 ml of glacial acetic acid was added while keeping the temperature at about 0°C ( 3°C). 

In the galvanic detector, the electrochemical detector consists of a noble metal like silver (Ag) or platinum (Pt), and a base metal such as lead (Pb) or tin (Sn), which acts as anode. The well-defined galvanic detector is immersed in the electrolyte solution. Various electrolyte solutions can be used, but commonly they may be a buffered lead acetate, sodium acetate and acetic acid mixture. The chemical reaction in the cathode with electrons generated in the anode may generate a measurable electrical voltage, which is a detectable signal for measurements of DO. The lead is the anode in the electrolyte solution, which is oxidised. Therefore the probe life is dependent on the surface area of the anode. The series of chemical reactions occurring in the cathode and anode is ... 

Properties of Perchloric Acid—Acetic Anhydride—Acetic Acid Mixtures. P 144... 

Fig 2 Properties of perchloric acid-acetic anhydride-acetic acid mixtures (from Ref 32)... 

Benzyl Alcohols. Benzyl alcohols of nearly all kinds undergo reduction when treated with acid in the presence of organosilicon hydrides. The most obvious exception to this is the behavior of benzyl alcohol itself. It resists reduction by the action of trifluoroacetic acid and triethylsilane, even after extended reaction times.26 Reducing systems consisting of triethylsilane and sulfuric acid/acetic acid or p-toluenesullonic acid/acetic acid mixtures also fail to reduce benzyl alcohol to toluene.134 As previously mentioned, substitution of boron trifluoride for trifluoroacetic acid results in the formation of modest yields of toluene, but only when a very large excess of the silane is used in order to capture the benzyl cation intermediate and suppress Friedel-Crafts oligomerization processes.129,143... 

However, reaction of 1,2,3-benzothiadiazole 3 with 30% hydrogen peroxide in a mixture of acetic acid and methanol for 45 days afforded product 37 (Equation 7) in 60% yield <1990CJC1950>. Oxidation of 1,2,3-benzothiadiazole 3 with a variety of other oxidizing agents (w-chloroperoxybenzoic acid, 30% hydrogen peroxide, hydrogen peroxide in methylene chloride-acetic acid mixtures, etc.) was unsuccessful. 

Swelling in water/acetic acid mixture shows a maximum of swelling shifting to higher temperatures when higher acetic acid concentrations increase (from 20 °C for 50 % acetic acid to 40 °C for 70 %). 

Water is preferentially sorbed by membranes, but much less from water-acetic acid mixtures than from ethanol/water mixtures [46],... 

A recent paper [69] presents a new type of PVA hybrid membrane prepared by hydrolysis followed by condensation of a PVA and a tetraethylorthosilicate (TEOS) mixture, which shows a significant performace in water-acetic acid mixture separation. The highest separation selectivity (1116) with a flux of 3.33xft)"2 kg m"2 h"1 at 30 °C for 10% mass of water in the feed has ben obtained by using the membrane containing 1 2 mass ratio of PVA and TEOS. The performance of these membranes was explained on the basis of a reduction of free volume and a decrease of the hydrophylic character owning to the formation of... 

NMR of Tributyltin Acetate-Acetic Acid Mixture. Corroborating the above indication is our observation that a mixture of TBT acetate and acetic acid in carbon tetrachloride shows only one resonance for... 

Figure 1. Variation of the position of acetyl proton resonance of TBT acetate-acetic acid mixtures with composition...

The toxicity characteristic leaching procedure may be subject to misinterpretation if the compounds under investigation are not included in the methods development or the list of contaminants leading to the potential for technically invalid results. However, an alternative procedure, the synthetic precipitation leaching procedure (SPLP, EPA SW-846 Method 1312) may be appropriate. This procedure is applicable for materials where the leaching potential due to normal rainfall is to be determined. Instead of the leachate simulating acetic acid mixture, nitric and sulfuric acids are utilized in an effort to simulate the acid rains resulting from airborne nitric and sulfuric oxides. 

The nitrosation of A-alkylureas in dioxane-acetic acid mixtures is governed by the expression v = fc[HN02][urea], at fixed pH, and dependent on rate-determining proton transfer from the protonated iV-alkyl-iV-nitrosourea to acetate anion the order of reactivity, which reflects relative impediment by the alkyl groups, is as for nitrosation in aqueous media (methyl- ethyl- propyl- butyl- > allyl-urea). 

The catalyst components are generally dissolved in methyl acetate which acts as both reactant and solvent. Other solvents may be used and in fact, upon several batch recycles where lower boiling products are distilled off, the solvent is an ethylidene diacetate-acetic acid mixture. Any water introduced in the reaction mixture will be consumed via ester and anhydride hydrolysis, therefore anhydrous conditions are warranted. Typical batch reaction examples are presented in Table 1. There is generally sufficient reactivity when carbon monoxide and hydrogen are present at 200-500 psi. Similar results were obtained from the pilot plant using a continuous stirred tank reactor (CSTR). The reaction can also be run continuously over a supported catalyst with a feed of methyl acetate, methyl iodide, CO, and hydrogen. 

Pyrido[2,3-, pyridazine derivatives 48 have been synthesized by refluxing equimolar amounts of an appropriate 5-benzylidene-2,2-dimethyl-l,3-dioxane-4,6-dione 47 with 5-amino-6-phenylpyridazin-3(2/7)-one 46 in methanol or a methanol acetic acid mixture. The electron-poor carbon atom of the polarized carbon-carbon double bond of 47 is the electrophile attacking C-4 of the 5-aminopyridazinone 46. Imino-enamine tautomerization of the intermediate is followed by ring closure and subsequent loss of acetone and carbon dioxide affording the reaction products 48 as stable crystalline solids in 70-90% yield (Scheme 9) <2000T2473>. 

Nitration of thienothiophenes (3) and (7) has been carried out under several different conditions, leading mainly to 2-nitro derivatives (76) and (77). Acetyl nitrate (HNO3/AC2O), nitric-acetic acid mixture and copper nitrate/acetic anhydride have been used. 

Farre et al. (14) described the determination of 5-nitrofurylacrylic acid (5-NFA) in wines from different areas in Spain. Determination of (5-NFA) was achieved by optimalization of the mobile phase by re versed-phase HPLC. The mobile phases studied were 25% methanol or 23% acetonitrile, deionized water, alone or together with acetic acid-acetate buffer (pH 4.4) or glacial acetic acid. The 5-NFA was separated onaLiChrosorbRP-18 (150 X 3.2-mm-ID) column eluted with acetonitrile water glacial acetic acid mixture (25 75 1.5) at the rate of 0.6 ml/min. The experiment was carried out at room temperature, and the detection wavelength was 360 nm. 

The reaction has been carried out using HCI either neat or in acetic acid,84 or in the presence of HgCh,83 BiCla86 or Me4NCl.M In acetic acid, mixtures of syn and anti adducts are produced,84 but reactions catalyzed by HgCl2 proceed by stereospecific anti addition.83-87 The reaction of r-butylacetylene affords the expected vinylic chloride, plus a mixture of isomeric dichloride adducts.84-88 The hydrochlorination of phenylacetyiene produces mixtures of syn and anti adducts in which the ratio is significantly affected by the solvent and catalyst used.84-89-90... 

The pyrido[l,2-a]pyrimidine (63 R = H) gave the 3-anilinomethylene derivative of type 224299 with ethyl iV-phenylformimidate, and it gave the bis compound (225) with triethyl orthoformate in a dimethylformamide-acetic acid mixture.300 The exact structure of 225 has not been elucidated. 

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