Phosphorus halides hydrolysis

Thiophosphoryl chloride dissolves sulphur and phosphorus freely when hot, but only sparingly when cold.2 Since the liquid is immiscible with water the hydrolysis proceeds only on the surface at first, as is usual with phosphorus halides. In this case the products are phosphoric acid, hydrogen chloride and sulphide and a little sulphur. It reacts with ethyl alcohol, giving ethyl chloride and ethyl thiophosphate ... 

Phosphorus acids or their salts containing P—H bonds are obtained commercially from hydrolysis of elemental phosphorus or phosphorus halides, under controlled conditions. Variations result in different product mixtures. Phosphorous acid forms in re-actions of PCI3 with Hp at 185-195°C ... 

As noted earlier in the alkylation study of a-fluoro phosphorus ylides, hydrolysis of the resultant a-fluoro phosphonium salts and a-fluorophosphonates do not necessarily parallel each other. This difference is again exhibited in the hydrolysis of the acylated products of the a-fluoro ylides. For example, the acylation product (10) is readily hydrolyzed at room temperature to give the desired a-fluoro-p-ketoester. The results of the acylation-hydrolysis of (4) with a variety of alkyl, cycloalkyl and aryl acyl halides are summarized in Table HI. 

A large number of 9-chloro and 9-bromo bases has been prepared by the action of phosphorus halides on the various alkaloids (11-14, 56, 97, 134, 135, 151, 166, 167). It seems probable that the replacement of hydroxyl by halogen in these reactions takes place with inversion. The hydrolysis of the halides, which is best carried out with silver nitrate in dilute nitric acid, also appears to involve a change in conflguration at... 

The reduced phospholes are never made directly by hydrogenation of phospholes most commonly, the ring is created in the desired state of reduction while phosphorus is in the oxide or sulfide form, and the process is completed by removal of these atoms. For the synthesis of 2- and 3-phospholenes, the McCormack cycloaddition of trivalent phosphorus halides with dienes, followed by hydrolysis, is the method of choice for obtaining the requisite P-oxides. This process, first described in US patents <53USP2663737,53USP2663738) by W. B. McCormack of the duPont Co., has... 

Phosphinous acids represent a promising new class of phosphorus ligands for Suzuki cross-couphngs of unactivated aryl chlorides. The hydrolysis of diorgano-phosphorus halides generates secondary phosphine oxides in an equilibrium with their less-stable phosphinous acid tautomers (Equation 2.29). 

Pentavalent phosphorus derivatives can be converted to phosphonyl halides or phosphine oxides by partial hydrolysis or by other oxygen donors. 

B. Reactions.—(/) Nucleophilic Attack at Phosphorus. A reinvestigation of the reaction between phosphorus trichloride and t-butylbenzene in the presence of aluminium chloride has shown that the product after hydrolysis is the substituted phosphinic acid (11), and not the expected phosphonic acid (12). Bis(A-alkylamino)phosphines have been reported to attack chlorodiphenyl phosphine with nitrogen, in the presence of a base, to give bis-(A-alkyl-A-diphenylphosphinoamino)phenylphosphines (13). In (13), the terminal phosphorus atoms are more reactive than the central one towards sulphur and towards alkyl halides. 

B. By Hydrolysis Reactions.—Details have appeared of the synthesis of dibenzophosphorin oxides (15) from 5-alkyldibenzophospholes, by reaction with methyl propiolate in the presence of water, and of confirmatory syntheses from phosphinic acid chlorides, as shown below. Evidence for the suggested mechanism of the ring-expansion reaction is presented. The hydrolysis of enamine phosphine oxides is an efficient, although somewhat indirect, method for the preparation of j8-ketoalkylphosphine oxides (16) [see Section 3(iii), for the preparation of enamine oxides]. Reasonable yields (48—66%) of trialkylphosphine oxides (17) have been obtained by the alkaline hydrolysis of the products from the pyrolysis at 220 °C of red phosphorus with alkyl halides, in the presence of iodine. 

Trippett and Stewart have shown that the phosphonium salts (11) derived from the reaction of phenyl di-t-butylphosphinite (12) with alkyl halides are highly resistant to hydrolysis and they suggest that this is due to the reluctance of phosphorus to accommodate two t-butyl groups in a trigonal-bipyramidal intermediate. 

Aromatic substituent effects due to phosphorus groups have been studied for a number of reactions.47 Thus ester hydrolysis and fluoride-displacement rates, for (56) and (57) respectively, are enhanced by phosphorus substituents (X = O or ), while the rate of hydrolysis of the halide (58) is enhanced for X = , but slowed for X = O.47 A perturbation M.O. analysis of these observations has been presented.48... 

A range of mechanisms is possible for the acidolysis of phosphorus amides, depending on the nucleophilicity of the departing amine. A recent study of phosphinic amides (160) in acidic media demonstrated that, when R2 is aryl, the presence of an o-Me group reduced the hydrolysis rate significantly, and also that the mechanism appears to be of an associative type.128 The phosphinic halides (161 X = Cl or F R = Me) are more reactive, probably for steric reasons, than the corresponding halides (161 R = Bu1) in 5 n2(P) solvolyses with aqueous acetone and with alkali. In the case of the t-butyl compounds, the fluoride is more reactive to OH- than is the chloride.129... 

Reactions of vinylphosphonates j2 with an equimolar amount of lithium dialkylcuprates J result in the formation of complexes 3 containing two different organic ligands. These complexes react with electrophiles in various ways. In each of them a diverse ligand plays the role of a nucleophile. Hydrolysis of 3 or alkylation with alkyl halides affords the corresponding phosphonates k and 5 comprising extended saturated carbon chains bonded to phosphorus. However, in a number of reactions with aldehydes, the complexes 3 were found to undergo almost completely selective transformation into carbinols 6... 

In the dissertation [11] amidophosphite 3d was brought into reaction with alkyl halides. In the 31P NMR spectrum the obtained quaternary salts 57 give a signal in the region of 51-54 ppm, characteristic of a quatemized phosphorus atom. The acid hydrolysis of the salts 57 leads to the previously described [49] 3-indolylphosphonic acid (56). 

The methods commonly used for preparation of disodium dihydrogen hypophosphate depend upon the oxidation of yellow or red phosphorus. Yellow phosphorus may be oxidized by air1 or by copper(II) nitrate.2,3 Red phosphorus may be oxidized by chlorite,4 hypochlorite,5,6 alkaline permanganate,7 hydrogen peroxide,7 or iodine.8 The phosphorus (III) halides, upon hydrolysis and treatment with iodine, yield some hypophosphate.9-11 Electrolytic oxidation of a phosphide of copper, nickel, or silver3 has also been used. 

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