Phosphorus pentoxide catalyst

Table 5. Air-Blowing of Fluxes With and Without Ferric Chloride and Phosphorus Pentoxide Catalysts...

The catalyst is washed with a little methanol and the combined filtrate is concentrated to a volume of about 25 ml by evaporation on a steam bath. Upon cooling to room temperature, white crystals separate which are filtered, washed with water, and dried in vacuo at room temperature over phosphorus pentoxide overnight. The weight of 6-chloro-7-sulfamyf... 

Surfactants are prepared which contain carboxylic acid ester or amide chains and terminal acid groups selected from phosphoric acid, carboxymethyl, sulfuric acid, sulfonic acid, and phosphonic acid. These surfactants can be obtained by reaction of phosphoric acid or phosphorus pentoxide with polyhydroxystearic acid or polycaprolactone at 180-190°C under an inert gas. They are useful as polymerization catalysts and as dispersing agents for fuel, diesel, and paraffin oils [69]. 

A mixture of monolauryl phosphate sodium salt and triethylamine in H20 was treated with glycidol at 80°C for 8 h to give 98% lauryl 2,3-dihydro-xypropyl phosphate sodium salt [304]. Dyeing aids for polyester fibers exist of triethanolamine salts of ethoxylated phenol-styrene adduct phosphate esters [294], Fatty ethanolamide phosphate surfactant are obtained from the reaction of fatty alcohols and fatty ethanolamides with phosphorus pentoxide and neutralization of the product [295]. A double bond in the alkyl group of phosphoric acid esters alter the properties of the molecule. Diethylethanolamine salt of oleyl phosphate is effectively used as a dispersant for antimony oxide in a mixture of xylene-type solvent and water. The composition is useful as an additive for preventing functional deterioration of fluid catalytic cracking catalysts for heavy petroleum fractions. When it was allowed to stand at room temperature for 1 month it shows almost no precipitation [241]. 

Asphalt feedstock (flux) is contacted with hot air at 200-280°C (400-550°F) to obtain desirable asphalt product. Both batch and continuous processes are in operation at present, but the batch process is more prevalent because of its versatihty. Nonrecoverable catalytic compounds include copper sulfate, zinc chloride, ferric chloride, aluminum chloride, phosphorus pentoxide, and others. The catalyst does not normally contaminate the process water effluent. 

Orthophosphoric acid and pyrophosphoric acid are preferred catalysts. Phosphorus pentoxide is catalytically active but no conclusive evidence has been described to show whether or not its activity depends on the presence of traces of water as promoter. Copper pyrophosphate and acid phosphates of cadmium are also good catalysts that the former probably owes its activity to partial conversion to acid or acidic salt under the polymerization conditions seems to be shown by the fact that there is an induction period. A composite prepared by calcining kiesel-guhr impregnated with orthophosphoric acid (the so-called solid phosphoric acid ) has found wide commercial use. 

Several catalysts have been recommended for the N-acetylation of carbazole with acetic anhydride boron trifluoride, phosphorus pentoxide, concentrated sulfuric acid, zinc chloride, and phosphoric acid all gave 9-acetylcarbazole in moderate to good yield. 9-Acetylcarbazole can also be prepared using the Vilsmeier complex of N,N-dimethylacetamide and phosgene. ... 

Ethyl-3-methylpyridine (also known as aldehyde-collidine ) has been prepared by heating aldehyde-ammonia aldehyde-ammonia and acetaldehyde or paraldehyde aldol-ammonia and ammonia paraldehyde and ammonia <> 11,12 acetamide,1 or acetamide and phosphorus pentoxide ethylene glycol and ammonium chloride ethylidene chloride or bromide and ammonia ethylidene chloride and acetamide, ethylamine, or n-amylamine crotonic acid and a calcium chloride-ammonia complex 1 and by passage of acetylene or acetaldehyde and ammonia over alumina and other catalysts. 

If asphalts having properties in the area above the blowing curve are desired, the producer may resort to the use of oxidation catalysts, which have been the subject of extensive study in recent years (7,12,19, 36, 56, 77,118). The only catalysts known to be in large scale use are ferric chloride and phosphorus pentoxide (36, 45). Table II illustrates that asphalts of the same ring and ball softening point oxidized in the presence of these catalysts have markedly higher 77° and 32° penetrations than another prepared from the same base stock in the absence of catalyst. 

However, this method is applied only when esterification cannot be effected by the usual acid—alcohol reaction because of the higher cost of the anhydrides. The production of cellulose acetate (see Fibers, CELLULOSE esters), phenyl acetate (used in acetaminophen production), and aspirin (acetylsalicylic acid) (see Salicylic acid) are examples of the large-scale use of acetic anhydride. The speed of acylation is gready increased by the use of catalysts (68) such as sulfuric acid, perchloric acid, trifluoroacetic acid, phosphorus pentoxide, zinc chloride, ferric chloride, sodium acetate, and tertiary amines, eg, 4- dimethylaminopyridine. 

In this section, consideration will be given to the actual processes of acetal- or ketal-formation and not to the more indirect methods by which acetals and ketals of the polyhydric alcohols may be synthesized from compounds (e.g. derivatives of the monosaccharides) containing preformed alkylidene or arylidene groupings. The condensation of a carbonyl compound with a glycol is facilitated by acidic catalysts, and, since the reaction is reversible, by dehydration. The catalysts most frequently employed are concentrated sulfuric, hydrochloric and hydro-bromic acids, gaseous hydrogen chloride, zinc chloride and cupric sulfate others are phosphorus pentoxide, sulfosalicylic acid, and anhydrous sodium sulfate. The formation of benzylidene compounds is promoted less efficiently by phosphorus pentoxide than by either concentrated sulfuric acid or concentrated hydrochloric acid 1" the reaction is assisted by chloro- and nitro-substituents on the aromatic nucleus, but hindered by methyl- and methoxy-groups.18... 

Alcohols react with a large excess of dimethoxymethane, (bp 41-42 °C) via an acetal exchange process at room temperature in the presence of acidic catalysts such as phosphorus pentoxide.459 474-475 The reaction was adapted to the construction of a 1,3-dioxane ring system in a synthesis of Mycalamide B [Scheme 4<257].47A After installing a MOM ether at a hindered secondary alcohol 257,1, the ketone was converted to its TBS enol ether 257J. Oxidation with wi-chloroperoxybenzoic acid returned a stable oxirane 257.4 that reacted with dimethoxymethane and phosphorus pentoxide to afford the desired L3-dioxane ring in 257 6 in 77% overall yield from 257J. Presumably, O-alkyla-... 

EtG was distilled under vacuum over phosphorus pentoxide (P2O5). A clear yellow liquid was obtained (100°C/50 mbar). A solution of EtsN (initiator) in dichloromethane (2 pL/mL) was added to the monomer (50% v/v) and the solution was stirred one hour at -20°C. A transparent viscous medium was obtained. An excess of phenyl isocyanate was then added to end-cap the polymer in the presence of DBTL as catalyst. The solution was stirred overnight at room temperature. Purification by precipitation into methanol was realized and the polymer was dried under vacuum at 50°C for 5 hours. 

Acylation of aromatic ethers yields the corresponding keto ethers. Typical examples are found in the conversion of anisole with aluminum chloride and appropriate acyl halide to p-methoxybutyrophenone (85%) and p-methoxyphenyl benzyl ketone (84%). Mild catalysts like iodine and phosphorus pentoxide are also effective. 

Dienolic forms of 1,4-dicarbonyl compounds are dehydrated by sulfuric acid, phosphorus pentoxide, and like catalysts to substituted furans. Diacylethylenes, RCOCH = CHCOR, undergo similar ring closure in reducing media. ... 

Dehydration of cyanohydrins to a, /3-olefinic nitriles has been accomplished by thionyl chloride, phosphorus pentoxide, or anhydrous potassium carbonate. A typical example is the preparation of 1-cyano-1-cyclopentene from cyclopentanone cyanohydrin (75%). Aluminum powder is the best of many catalysts studied for the dehydration of ethylene cyanohydrin to acrylonitrile, HjC=CHCN (80%). ... 

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