Phosphorus trichloride

Violently decomposed by water, forming hydrochloric acid and phosphorous acid.2 

Acetic Acid. Residue in preparation of acetyl chloride from PC13 and acetic acid may decompose violently with evolution of flammable phosphine.3 4 

Carboxylic Acids. Use of PC13 as chlorinating agent for carboxylic acids may result in explosion when product is distilled.5-7 

Dimethyl Sulfoxide. Reacts explosively with PC13.8 Hydroxylamine. Ignites on contact with PC13.9 Metals. K ignites in PC13 molten Na explodes on contact.10 Nitric or Nitrous Acids. Explodes on contact with either acid.11 Water. Reacts violently on contact with water with liberation of some diphosphane that ignites.3 

Vapor severely irritates the respiratory system. The vapor and liquid burn the eyes and skin. Swallowing causes severe internal irritation and damage. Prolonged exposure to low concentrations of vapor may cause lung damage. Avoid breathing vapor. Prevent contact with eyes and skin.2 TLV-TWA 0.2 ppm (1 mg/m3) TLV-STEL 0.5 ppm (2.8 mg/m3).12 

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Pure phosphine can be prepared by the reduction of a solution of phosphorus trichloride in dry ether with lithium aluminium hydride ... 

Phosphonic acid, H3PO3, often called just phosphorous acid , is prepared by the hydrolysis of phosphorus trichloride a stream of air containing phosphorus trichloride vapour is passed into ice-cold water, and crystals of the solid acid separate ... 

The trichloride is obtained as a liquid, boiling point 349 K, when a jet of chlorine burns in phosphorus vapour. Care must be taken to exclude both air and moisture from the apparatus since phosphorus trichloride reacts with oxygen and is vigorously hydrolysed by water, fuming strongly in moist air. The hydrolysis reaction is ... 

The reaction with oxygen converts phosphorus trichloride to phosphorus trichloride oxide (oxychloride), POCI3 the trichloride is able to remove oxygen from some molecules, for example sulphur trioxide... 

Phosphorus trichloride reacts with chlorine in excess to give phosphorus pentachloride, an equilibrium being set up ... 

Phosphorus pentachloride is prepared by the action of chlorine on phosphorus trichloride. To push the equilibrium over to the right, the temperature must be kept low and excess chlorine must be present. Hence the liquid phosphorus trichloride is run dropwise into a flask cooled in ice through which a steady stream of dry chlorine is passed the solid pentachloride deposits at the bottom of the flask. 

Phosphorus pentachloride sublimes and then dissociates on heating, dissociation being complete at 600 K. It is attacked by water, yielding first phosphorus trichloride oxide, thus ... 

Alkyl Phosphites. The Interaction of Phosphorus Trichloride and Alcohols. 

Phosphorus trichloride reacts readily with three equivalents of an alcohol e.g, ethanol, in the presence of a tertiary amine such as pyridine, dimethyl-aniline, or diethylaniline, to form triethyl phosphite and hydrogen chloride, the latter being immediately neutralised by the tertiary amine. 

The following preparation of triethyl phosphite illustrates the interaction of phosphorus trichloride and ethanol in the presence of dimethylaniline the preparation of di-isopropyl hydrogen phosphite illustrates that of phosphorus trichloride and isopropanol in the absence of a tertiary amine. 

Place 38 ml. of isopropanol in a two-necked 500 ml. round-bottomed flask fitted with (a) a reflux water-condenser having a calcium chloride tube at the top, and (b) a dropping-funnel. Cool the flask in ice-water and then run 13 5 ml. of phosphorus trichloride in from the dropping-funnel during 15 minutes. Then allow the reaction-mixture to attain room temperature. Now replace the condenser and the... 

The Bart reaction has now been extended to the synthesis of arylphosphonic acids by the interaction of the diazonium fluoroborate and phosphorus trichloride (Doak and Freedman, 1951). 

Phosphorus trichloride. The reaction is not quite quantitative, for example ... 

Method 1. Use the apparatus depicted iu Fig. Ill, 56, 1, but omit the thermometer also attach a cotton wool (or calcium chloride) tube to the side arm of the filter fiask receiver in order to prevent the entrance of moisture into the apparatus. Mount the reaction fiask in a water bath e.g., a large beaker or other convenient vessel). It is important that all the apparatus be perfectly dry, since both phosphorus trichloride and acetyl chloride are decomposed by water. The set-up should be assembled in the fume eupboard. 

Bromination of fatty acids in the a-position can be effected quite readily in the presence of phosphorus trichloride, red phosphorus or pyridine as catalysts or halogen carriers with acetic acid, the addition of acetic anhydride (to ensure the absence of water) improves the yield and facilitates the bromination. Examples are —... 

Phosphorus trichloride in benzene is reported to effect mild and fast cydization. It has been used for synthesis of 2,3-dialkyl- and 2,3-diaryl-indoles[8-ll]. Table 7.2 presents some typical Fischer indolization reactions using both the traditional and more recently developed reaction conditions. 

Reaction with phosphorus trihalides (Section 4 13) Phosphorus trichloride and phosphorus tribromide convert alcohols to alkyl halides... 

This method of a bromination of carboxylic acids is called the Hell-Volhard-Zelinsky reaction This reaction is sometimes carried out by using a small amount of phosphorus instead of phosphorus trichloride Phosphorus reacts with bromine to yield phosphorus tribromide as the active catalyst under these conditions... 

Hydroxylamine Barium oxide and peroxide, carbonyls, chlorine, copper(II) sulfate, dichromates, lead dioxide, phosphorus trichloride and pentachloride, permanganates, pyridine, sodium, zinc... 

Lead dioxide Aluminum carbide, hydrogen peroxide, hydrogen sulfide, hydroxylamine, ni-troalkanes, nitrogen compounds, nonmetal halides, peroxoformic acid, phosphorus, phosphorus trichloride, potassium, sulfur, sulfur dioxide, sulfides, tungsten, zirconium... 

Nitrous acid Phosphine, phosphorus trichloride, silver nitrate, semicarbazone... 

Phosphorus trichloride Acetic acid, aluminum, chromyl dichloride, dimethylsulfoxide, hydroxylamine, lead dioxide, nitric acid, nitrous acid, organic matter, potassium, sodium water... 

Organophosphorus Derivatives. Neopentyl glycol treated with pyridine and phosphorus trichloride in anhydrous dioxane yields the cycHc hydrogen phosphite, 5,5-dimethyl-l,3-dioxaphosphorinane 2-oxide (2) (32,33). Compounds of this type maybe useful as flameproofing plasticizers, stabilizers, synthetic lubricants, oil additives, pesticides, or intermediates for the preparation of other organophosphoms compounds (see Flame retardants Phosphorus compounds). 

Phosphorus Trichloride and Phosphorus Ouychloride, Monsanto Chemical Intermediates Co., St. Louis, Mo., 1977. 

Phosphorus Trichloride ia Chemical Products Synopsis, MaimsviUe Chemical Products Corp., Asbury Park, N.J., June, 1992 Phosphorus Oyychloride, Ibid,... 

Amino-pyridazines and -pyridazinones react with monomethyl- or iV,A-dimethyl-formamide and other aliphatic amides in the presence of phosphorus trichloride, thionyl chloride, phosgene or benzenesuUonyl chloride to give mono- or di-alkylaminomethyl-eneamino derivatives. The same compounds can be prepared conveniently with A,iV-dimethylformamide dimethyl acetal in high yield (Scheme 50). 

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