Petroleum residues reagents

A solution of 6.3 g (0.9 moles) ethoxyacetylene in 50 ml ether is added dropwise during 30 min to a Grignard reagent prepared from 2.18 g (90 mg-atoms) magnesium and 9.81 g (90 mmoles) ethyl bromide. The reaction mixture is stirred for 1 hr at room temperature and then a solution of 3 g (9 mmoles) 3) -acetoxyandrost-5-en-I7-one in 50 ml dry ether is added dropwise. The mixture is refluxed for 1 hr and after cooling to 0° poured into 100 ml of an aqueous ammonium chloride solution. The aqueous solution is extracted with ether, and the organic extract is washed with ammonium chloride solution and water, dried, and evaporated. The residue is chromatographed on 130 g alumina (activity III). Elution with petroleum ether-benzene (1 1) yields, after crystallization from acetone-hexane, 1.27 g (35%) 3j5-acetoxy-17a-ethoxyethynylandrost-5-en-17) -ol mp 138-139° Ho -122°. 

The most important olefins used for the production of petrochemicals are ethylene, propylene, the butylenes, and isoprene. These olefins are usually coproduced with ethylene by steam cracking ethane, LPG, liquid petroleum fractions, and residues. Olefins are characterized by their higher reactivities compared to paraffinic hydrocarbons. They can easily react with inexpensive reagents such as water, oxygen, hydrochloric acid, and chlorine to form valuable chemicals. Olefins can even add to themselves to produce important polymers such as polyethylene and polypropylene. Ethylene is the most important olefin for producing petrochemicals, and therefore, many sources have been sought for its production. The following discusses briefly, the properties of these olefmic intermediates. 

Dehydrohalogenation is readily accomplished by heating with 2% potassium hydroxide in 95% ethyl alcohol. In order to separate the dehydrohalogenated methoxychlor from the reaction mixture, the alcohol is allowed to evaporate, and the residue is taken up in petroleum ether and washed with water. Most batches of even reagent grade petroleum ether contain substances which after contact with potassium hydroxide will yield... 

B Add 30 g (II) over one-half hour to 420 ml methyl iodide and let stand fifteen hours at 5°. Separate the iodomethylate which precipitates, dry briefly at 50° and heat with vigorous stirring at 80° for two hours with 60 g NaCN in 1 L water. Extract with CHC13, dry and evaporate in vacuum the extract and dissolve the residue in 250 ml ether. Filter, evaporate in vacuum to a few ml and precipitate the acetonitrile (III) by adding petroleum ether. The acetonitrile can also be prepared directly from the indole via the Grignard reagent as given elsewhere here. 

The bomb method for sulfur determination (ASTM D129) uses sample combustion in oxygen and conversion of the sulfur to barium sulfate, which is determined by mass. This method is suitable for samples containing 0.1 to 5.0% w/w sulfur and can be used for most low-volatility petroleum products. Elements that produce residues insoluble in hydrochloric acid interfere with this method this includes aluminum, calcium, iron, lead, and silicon, plus minerals such as asbestos, mica, and silica, and an alternative method (ASTM D1552) is preferred. This method describes three procedures the sample is first pyrolyzed in either an induction furnace or a resistance furnace the sulfur is then converted to sulfur dioxide, and the sulfur dioxide is either titrated with potassium iodate-starch reagent or is analyzed by infrared spectroscopy. This method is generally suitable for samples containing from 0.06 to 8.0% w/w sulfur that distill at temperatures above 177°C (351°F). 

DibenzotelluropheneIn an uncommon use as synthetic reagent, tellurium dichloride (10.6 g 53.4 mmol) was added to 2,2 -dilithiobiphenyl (61.6 nmmol), in dry ether. The stirred mixture is allowed slowly to warm to 20°C. After 15 h the mixture is hydrolysed, filtered and the organic phase is separated. The ether is evaporated, the pasty residue is dissolved in petroleum ether (b.p. 40-60°C) and the solution is chromatographed on a column of neutral alumina. Yield 8.0 g (54%) m.p. 94°C. 

The Grignard reagent is prepared from 6 gms. (2 mols.) of dry magnesium, and 39 gms. (2 mols.) of ethyl iodide (redistilled), as described in Preparation 19, 120 c.cs. of anhydrous ether being used. 23 gms. (1 mol.) of dry, finely divided benzophenone are added, the flask being cooled if the reaction becomes too vigorous. The mixture is then heated 6 hours on a water bath, treated with dilute acid, extracted with ether, the ether removed on a water bath, and the residue fractionated under reduced pressure, the fraction 169°—170° at 18 mms. being separately collected and recrystallised from petroleum ether. 

Four ml plasma are extracted twice with 4 ml of the following solvent methyl acetate/petroleum ether/ ethanol (66 33 1.5 v/v). After centrifugation, the organic extracts are evaporated to dryness, dissolved into 4 ml hexane and again extracted twice with 2 ml Claisen s alkali reagent. The alkaline solutions are acidified with 1 ml N HC1 (pH = 1.5) and then extracted twice with 4 ml hexane. This last solution is evaporated to dryness and the residue dissolved in the necessary amount of acetone and then transferred into a hemolysis tube. 

Tellurium (O-ethyl dithiocarbonate) chloride was similarly obtained using tellurium tetrachloride as reagent and dichloromethane as the solvent. The reaction was carried out at 20°. After stirring of the reaction mixture for 2 h, the solvent was evaporated under reduced pressure. The residue was washed with boiling light petroleum ether and then recrystallized from chloroform/light petroleum ether2. 

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