Phosphorous acid chloride

Phosphoric acid chloride and thiophosphoric acid chloride pyrididium betaines (I) which are easily prepared by reacting P401Qt P OgS. and P4S1Q, respectively, with phosphorus oxychldride or phdspnorus thio-chloride in the presence of pyridine (1.), are of interest for the synthesis of substituted phosphates and thiophosphates. 

With phosphoryl chloride in alkali, imidazole gives the diphosphoryl imidazole (71) while 1-methylimidazole gives an analogous product. Such iV-phosphorylimidazoles play an important role in enzymic transphosphorylation. When two moles of imidazole (or benzimidazole) react with one mole of dialkyl (or diaryl) phosphoric acid chloride, the compounds (72) are formed, and di- and tri-imidazolides of phosphoric acid (e.g. 73) can be obtained similarly from phosphoric acid dichloride or from phosphoryl chloride (Scheme... 

Nearly all commercial acetylations are realized using acid catalysts. Catalytic acetylation of alcohols can be carried out using mineral acids, eg, perchloric acid [7601-90-3], phosphoric acid [7664-38-2], sulfuric acid [7664-93-9], benzenesulfonic acid [98-11-3], or methanesulfonic acid [75-75-2], as the catalyst. Certain acid-reacting ion-exchange resins may also be used, but these tend to decompose in hot acetic acid. Mordenite [12445-20-4], a decationized Y-zeohte, is a useful acetylation catalyst (28) and aluminum chloride [7446-70-0], catalyzes / -butanol [71-36-3] acetylation (29). 

Jicyylic anhydride is formed by treatment of the acid with acetic anhydride or by reaction of acrylate salts with acryloyl chloride. Jicryloylchloride is made by reaction of acryhc acid with phosphorous oxychloride, or benzoyl or thionyl chloride. Neither the anhydride nor the acid chloride is of commercial interest. 

Israel Mining Industries developed a process in which hydrochloric acid, instead of sulfuric acid, was used as the acidulant (37). The acidulate contained dissolved calcium chloride which then was separated from the phosphoric acid by use of solvent extraction using a recyclable organic solvent. The process was operated commercially for a limited time, but the generation of HCl fumes was destmctive to production equipment. 

The FCC is to food-additive chemicals what the USP—NF is to dmgs. In fact, many chemicals that are used in dmgs also are food additives (qv) and thus may have monographs in both the USP—NF and in the FCC. Examples of food-additive chemicals are ascorbic acid [50-81-7] (see Vitamins), butylated hydroxytoluene [128-37-0] (BHT) (see Antioxidants), calcium chloride [10043-52-4] (see Calcium compounds), ethyl vanillin [121-32-4] (see Vanillin), ferrous fumarate [7705-12-6] and ferrous sulfate [7720-78-7] (see Iron compounds), niacin [59-67-6] sodium chloride [7647-14-5] sodium hydroxide [1310-73-2] (see lkaliand cm ORiNE products), sodium phosphate dibasic [7558-79-4] (see Phosphoric acids and phosphates), spearmint oil [8008-79-5] (see Oils, essential), tartaric acid [133-37-9] (see Hydroxy dicarboxylic acids), tragacanth [9000-65-1] (see Gums), and vitamin A [11103-57-4]. 

Urea—Phosphate Type. Phosphoric acid imparts flame resistance to ceUulose (16,17), but acid degradation accompanies this process. This degradation can be minimized by iacorporation of urea [57-13-6]. Ph osph oryl a ting agents for ceUulose iaclude ammonium phosphate [7783-28-0] urea—phosphoric acid, phosphoms trichloride [7719-12-2] and oxychloride [10025-87-3] monophenyl phosphate [701-64-4] phosphoms pentoxide [1314-56-3] and the chlorides of partiaUy esterified phosphoric acids (see Cellulose esters, inorganic). 

Hydrogen Chloride as By-Product from Chemical Processes. Over 90% of the hydrogen chloride produced in the United States is a by-product from various chemical processes. The cmde HCl generated in these processes is generally contaminated with impurities such as unreacted chlorine, organics, chlorinated organics, and entrained catalyst particles. A wide variety of techniques are employed to treat these HCl streams to obtain either anhydrous HCl or hydrochloric acid. Some of the processes in which HCl is produced as a by-product are the manufacture of chlorofluorohydrocarbons, manufacture of aUphatic and aromatic hydrocarbons, production of high surface area siUca (qv), and the manufacture of phosphoric acid [7664-38-2] and esters of phosphoric acid (see Phosphoric acid and phosphates). 

Isopropylnaphthalenes can be prepared readily by the catalytic alkylation of naphthalene with propjiene. 2-lsopropylnaphthalene [2027-17-0] is an important intermediate used in the manufacture of 2-naphthol (see Naphthalenederivatives). The alkylation of naphthalene with propjiene, preferably in an inert solvent at 40—100°C with an aluminum chloride, hydrogen fluoride, or boron trifluoride—phosphoric acid catalyst, gives 90—95% wt % 2-isopropylnaphthalene however, a considerable amount of polyalkylate also is produced. Preferably, the propylation of naphthalene is carried out in the vapor phase in a continuous manner, over a phosphoric acid on kieselguhr catalyst under pressure at ca 220—250°C. The alkylate, which is low in di- and polyisopropylnaphthalenes, then is isomerized by recycling over the same catalyst at 240°C or by using aluminum chloride catalyst at 80°C. After distillation, a product containing >90 wt % 2-isopropylnaphthalene is obtained (47). 

Properties and Reactions. Phosphoms sulfochloride [3982-91-0] (thiophosphoryl chloride), PSCI3, is a colorless fuming Hquid andis made by the reaction of phosphoms trichloride with sulfur and by the reaction of PCI3 with P2S3. Phosphoms sulfochloride is dimorphic in the soHd state. It reacts with water, forming either phosphoric acid or dichlorothiophosphoric acid [14500-94-8] depending on the reaction conditions. 

Phosphonic (phosphorous) acid, produced by hydrolysis of PCl, is for the most part consumed captively. It has also been offered as a flaked product and a 70 wt % solution by Rhc ne-Poulenc. Phosphonic acid is a by-product from manufacturing carboxyHc acid chlorides and alkaH peroxides. Additional by-product phosphonic acid is recovered in the manufacture of phosphinic acid. 

Devising an economical method of producing agricultural-grade potassium phosphates from potassium chloride and wet-process phosphoric acid has been the subject of intense agricultural—chemical research (37—39). Limited quantities have been produced industrially. The impact on the overall quantities of phosphoms and potassium compounds consumed by the fertilizer industry is small. Because potassium phosphates are an excellent source of two essential fertilizer elements, this research is expected to continue. 

Currently, almost all cumene is produced commercially by two processes ( /) a fixed-bed, kieselguhr-supported phosphoric acid catalyst system developed by UOP and (2) a homogeneous AlCl and hydrogen chloride catalyst system developed by Monsanto. 

Aromatic amines form addition compounds and complexes with many inorganic substances, such as ziac chloride, copper chloride, uranium tetrachloride, or boron trifluoride. Various metals react with the amino group to form metal anilides and hydrochloric, sulfuric, or phosphoric acid salts of aniline are important intermediates in the dye industry. 

The vapor-phase conversion of aniline to DPA over a soHd catalyst has been extensively studied (18,22). In general, the catalyst used is pure aluminum oxide or titanium oxide, prepared under special conditions (18). Promoters, such as copper chromite, nickel chloride, phosphoric acid, and ammonium fluoride, have also been recommended. Reaction temperatures are usually from 400 to 500°C. Coke formed on the catalyst is removed occasionally by burning. In this way, conversions of about 35% and yields of 95% have been reported. Carba2ole is frequently a by-product. 

Contaminants and by-products which are usually present in 2- and 4-aminophenol made by catalytic reduction can be reduced or even removed completely by a variety of procedures. These include treatment with 2-propanol (74), with aUphatic, cycloaUphatic, or aromatic ketones (75), with aromatic amines (76), with toluene or low mass alkyl acetates (77), or with phosphoric acid, hydroxyacetic acid, hydroxypropionic acid, or citric acid (78). In addition, purity may be enhanced by extraction with methylene chloride, chloroform (79), or nitrobenzene (80). 

A Phenylamino)phenol. This phenol (17) is slightly soluble ia ethanol, diethyl ether, acetone, benzene, and water. The compound is made by heating resorciaol and aniline at 200°C ia the preseace of aqueous phosphoric acid or calcium chloride. Ia another process, 3-amiaophenol is heated with aniline hydrochloride at 210—215°C (181). 

Sahcyhc acid can be converted to sahcyloyl chloride [1441 -87-8] hy reaction with thionyl chloride in boiling ben2ene. The formation of acyl haUde may also extend to reaction with the phenoHc hydroxyl. The reaction with phosphoms tri- and pentachlorides is not restricted to the formation of the acid chloride. Further interaction of the phosphoms haUde and the phenoHc hydroxyl results in the formation of the phosphoric or phosphorous esters. 

This route to acid chlorides is often preferred over the alternative use of phosphoms trichloride because the by-products, SO2 and HCl, are gaseous and easily removed. On the other hand, the use of phosphoms trichloride yields phosphorous acid as a by-product. This can decompose exothermically with evolution of toxic and flammable phosphine if overheated, however, phosphorous acid is saleable as a valuable by-product on a commercial scale. Ma.nufa.cture. Thionyl chloride may be made by any of the following reactions ... 

Acylation. To achieve acylation of thiophenes, acid anhydrides with phosphoric acid, iodine, or other catalysts have been widely used. Acid chlorides with AlCl, SnCl, ZnCl2, and BF also give 2-thienylketones. AH reactions give between 0.5 and 2.0% of the 3-isomer. There has been much striving to find catalyst systems that minimize the 3-isomer content attempting to meet to customer specifications. The standard procedure for formylation is via the Vil smeier-H a ack reaction, using phosphoms o xycbl o ri de / /V, / V- dim e tb yl fo rm a m i de (POCl /DMF) or /V-m ethyl form an i1 i de. 

Poly(vinyl nitrate) has been prepared and studied for use in explosives and rocket fuel (104,105). Poly(vinyl alcohol) and sulfur trioxide react to produce poly(vinyl sulfate) (106—111). Poly(vinyl alkane sulfonate)s have been prepared from poly(vinyl alcohol) and alkanesulfonyl chlorides (112—114). In the presence of urea, poly(vinyl alcohol) and phosphoms pentoxide (115) or phosphoric acid (116,117) yield poly(vinyl phosphate)s. 

Zinc chloride is a Lewis acid catalyst that promotes cellulose esterification. However, because of the large quantities required, this type of catalyst would be uneconomical for commercial use. Other compounds such as titanium alkoxides, eg, tetrabutoxytitanium (80), sulfate salts containing cadmium, aluminum, and ammonium ions (81), sulfamic acid, and ammonium sulfate (82) have been reported as catalysts for cellulose acetate production. In general, they require reaction temperatures above 50°C for complete esterification. Relatively small amounts (<0.5%) of sulfuric acid combined with phosphoric acid (83), sulfonic acids, eg, methanesulfonic, or alkyl phosphites (84) have been reported as good acetylation catalysts, especially at reaction temperatures above 90°C. 

Cumene as a pure chemical intermediate is produced in modified Friedel-Crafts reaction processes that use acidic catalysts to alkylate benzene with propylene (see Alkylation Friedel-CRAFTSreactions). The majority of cumene is manufactured with a soHd phosphoric acid catalyst (7). The remainder is made with aluminum chloride catalyst (8). 

In laboratory preparations, sulfuric acid and hydrochloric acid have classically been used as esterification catalysts. However, formation of alkyl chlorides or dehydration, isomerization, or polymerization side reactions may result. Sulfonic acids, such as benzenesulfonic acid, toluenesulfonic acid, or methanesulfonic acid, are widely used in plant operations because of their less corrosive nature. Phosphoric acid is sometimes employed, but it leads to rather slow reactions. Soluble or supported metal salts minimize side reactions but usually require higher temperatures than strong acids. 

---