Acetic acid and nitrogen

Agrawal and Mushran studied the kinetics of the silver ion-catalysed oxidation of acetamide. The stoichiometry is uncertain, but acetic acid and nitrogen are the main products. The rate is approximately first-order with respect to both peroxodisulphate and silver ions, and is almost independent of the substrate concentration. No definite conclusions regarding the mechanism can be drawn, but the kinetics suggest a chain process. Agrawal et report similar results for the oxidation of formamide. 

The criteria for selection of a suitable oxidation catalyst for heavy-duty ethanol-fiielled vehicles in city traffic involve aspects such as regulated emissions (CO, NOx, hydrocarbons and particulates), emissions of unbumed ethanol, formation of acetaldehyde, acetic acid, and nitrogen dioxide. The oxidation of nitric oxide to nitrogen dioxide can be a problem when using highly active precious metal catalysts. This is especially the case when using platinum as active material (Pettersson et ai, 1994). NO2 is more toxic than NO and should be minimized at street levels. The catalyst with the highest activity for ethanol conversion is not necessarily the best choice if the minimum environmental impact is the objective. 

The selection of the optimal catalyst for heavy-duty ethanol vehicles in city traffic from the enviromuental point-of-view is a question of choosing tlie oxidation catalyst which produces the least hazardous combination of reaction products. It is not sufficient to consider only the activity for eliminating the regulated emissions. Considering fonnation of acetaldehyde, acetic acid and nitrogen dioxide, as well as emissions of unburaed ethanol and carbon monoxide, tliere are some interesting catalyst combinations, which will be investigated further both in laboratory and frill-scale experiments. 

Anhydrous ammonia is normally analy2ed for moisture, oil, and residue. The ammonia is first evaporated from the sample and the residue tested (86). In most instances, the amount of oil and sediment ia the samples are insignificant and the entire residue may be assumed to be water. For more accurate moisture determinations, the ammonia can be dissociated into nitrogen and hydrogen and the dewpoint of the dissociated gas obtained. This procedure works well where the concentration of water is in the ppm range. Where the amount of water is in the range of a few hundredths of a percent, acetic acid and methanol can be added to the residue and a Karl Fischer titration performed to an electrometricaHy detected end point (89—92). 

B. Tropohne. In a 1-1., three-necked, round-bottomed flask equipped with a mechanical stirrer, addition funnel, and reflux condenser are placed 500 ml. of glacial acetic acid and then, cautiously, 100 g. of sodium hydroxide pellets. After the pellets have dissolved, 100 g. of 7,7-dichlorobicyclo[3.2.0]hept-2-en-6-one is added and the solution is maintained at reflux under nitrogen for 8 hours. Concentrated hydrochloric acid is then added until the mixture is about pH 1 approximately 125 ml. of acid is required. After the addition of 1 1. of benzene, the mixture is filtered and the solid sodium chloride is washed with three 100-ml. portions of benzene. The two phases of the filtrate are separated and the aqueous phase is transferred to a 1-1. continuous extractor (Note 8) which is stirred magnetically. The combined benzene phase is transferred to a 2-1. pot connected to the extractor and the aqueous phase is extracted for 13 hours. Following distillation of the benzene, the remaining orange liquid is distilled under reduced pressure... 

Into a suspension of 8 g of sodium acetate m 400 mL of a solution of 1 part acetic acid and 10 parts fluorotnchloromethane is passed at -75 C a stream of fluonne diluted to 10% with nitrogen The reacuon is stirred with a Vibromixer A solution of 4-methylacetanilide (20 mmol) in a mixture of dichloromethane and fluorotnchloromethane cooled to -75 °C i s added to 20 mmol of acetyl hypofluonte as determined by titration with potassium iodide After 5 min the mixture is poured into water, and the orgamc layer is washed with sodium bicarbonate soluaon and dried over anhydrous magnesium sulfate After concentrauon and column chromatography over silica gel and elution with chloroform, 2-fluoro-4-methylacetanilide IS obtained m 85% yield... 

The mixture is stirred under nitrogen at room temperature for 15 minutes. It is then acidified with acetic acid and the solvent is removed under vacuum at room temperature. About 20 cc of water is added and the product is extracted into 150 cc of ethyl acetate. The ethyl acetate solution is washed with saturated sodium bicarbonate and then with water. It is then dried over sodium sulfate and taken to dryness to give an amorphous solid. 

Thereafter, the ammonia was evaporated, 1 liter of water was added thereto and the aqueous phase was separated and extracted with ether. The ethereal phases now combined were washed with water until the wash waters were neutral, then dried over sodium sulfate, filtered and distilled to dryness to obtain 21 grams of product, which was dissolved in 210 cc of ethanol under reflux. Next, 21 cc of acetic acid and 21 grams of Girard s reactant T were added thereto. The mixture was agitated for hours under an atmosphere of nitrogen while maintaining the reflux. Thereafter, the reaction mixture was cooled to room temperature and then poured into 1,050 cc of water. Next, 155 cc of 2 N sodium hydroxide solution were added and finally the mixture was extracted with ether. 

D) 1-p-Chlorobenzoyl-2-Methyl-S-Methoxy-3-lndolylacetic Acid A mixture of 1 g ester and 0.1 g powdered porous plate is heated in an oil bath at 210°C with magnetic stirring under a blanket of nitrogen for about 2 hours. No intensification of color (pale yellow) occurs during this period. After cooling under nitrogen, the product is dissolved in benzene and ether, filtered, and extracted with bicarbonate. The aqueous solution is filtered with suction to remove ether, neutralized with acetic acid, and then acidified weakly with dilute hydrochloric acid. The crude product (0.4 g, 47%) is recrystallized from aqueous ethanol and dried in vacuo at 65°C MP 151°C. 

More than 90 years ago Bamberger (1897) discovered that iV-nitrosoacetanilide decomposes easily in benzene to give biphenyl, acetic acid, and molecular nitrogen (Scheme 2-24). 

The balloon was removed briefly while aliquots were taken. The flask was flushed again with nitrogen and the balloon was then replaced. Thin-layer chromatographic analyses were carried out on glass plates coated with silica gel G which were purchased from Analtech, Newark, Delaware. With a 10 2 3 (v/v/v) solution of 1-butanol, acetic acid, and water as developing solvent, the Rf values for the product and L-cysteine hydrochloride are 0.19 and 0.25, respectively. 

As a general rule, peracetylation is most useful for compounds below Mr 2000, particularly those that have been reduced with sodium borohydride and still contain some salt. The best procedure for peracetylation is based on the method of Bourne and coworkers. Samples are dissolved in 2 1 (v/v) trifluoroacetic anhydride-acetic acid and the solutions kept for 10 min at room temperature. Reagents are removed under a stream of nitrogen, and a solution of the product in chloroform is washed with water to remove salts, and dried the peracetylated sample is dissolved in methanol for the f.a.b. analysis. 

Figure 9. COj (MW=45) and COj (MW=44) response curves for a ethylene -t- oxygen pulse to a continuous acetic acid saturated nitrogen stream after it is passed over the Pd-Au w/KOAc catalyst with different ethylene to oxygen ratios (e.g., 4 to 1).

Polarography has also been applied to the determination of potassium in seawater [535]. The sample (1 ml) is heated to 70 °C and treated with 0.1 M sodium tetraphenylborate (1 ml). The precipitated potassium tetraphenylborate is filtered off, washed with 1% acetic acid, and dissolved in 5 ml acetone. This solution is treated with 3 ml 0.1 M thallium nitrate and 1.25 ml 2M sodium hydroxide, and the precipitate of thallium tetraphenylborate is filtered off. The filtrate is made up to 25 ml, and after de-aeration with nitrogen, unconsumed thallium is determined polarographically. There is no interference from 60 mg sodium, 0.2 mg calcium or magnesium, 20 pg barium, or 2.5 pg strontium. Standard eviations at concentrations of 375, 750, and 1125 pg potassium per ml were 26.4, 26.9, and 30.5, respectively. Results agreed with those obtained by flame photometry. 

A solution of 10 ml of 10 N aqueous KOH diluted to 25 ml with absolute ethanol was added dropwise over a period of 30 min to a well-stirred mixture of 0.4 g-atom (12.4 g) of finely divided white phosphorus, 1.2 mol (85.2 g) of acrylamide, and 200 ml of absolute ethanol under a nitrogen atmosphere. The temperature was maintained at -5 to 0°C by a cooling bath. After stirring for an additional 45 min, the white solid generated was recovered by filtration. This solid was dissolved in 125 ml of hot glacial acetic acid, and the solution was cooled to room temperature. (Any unreacted white phosphorus could be removed at this point by decantation under a nitrogen atmosphere.) The solution was filtered through diatoma-ceous earth, diluted with 600 ml of absolute ethanol, and cooled at 5°C for 30 min. The resultant white solid was collected by filtration, washed with absolute ethanol, and dried to produce the pure tris(2-carbamoylethyl)phosphine oxide in 74% yield. 

A unique Pd(II)-promoted ortfto-esterification of 2,5-diphenyloxazole has been described [26], When 2,5-diphenyloxazole was heated with 2.5 equivalents of Pd(OAc>2 in acetic acid and CCLt, regioselective palladation took place, giving rise to arylpalladium(n) o-complex 31 in almost quantitative yield. The regioselectivity observed reflects the strong coordination ability of the oxazole nitrogen atom to the palladium atom. Complex 31 was then dissolved in MeOH-THF (1 1) and the solution was stirred at 0 °C to produce 2-(5 -phenylthiazol2-yl)-benzoate 32. A... 

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