Dithiophosphoric acid

DiaIkyl or diaryl dithiophosphoric acids are obtained readily from alcoholysis of phosphoms(V) sulfide. Thus, P4S q reacts with ethyl alcohol as follows ... 

Dialkyl and diaryl dithiophosphoric acids are the bases of many high pressure lubricants, oil additives (see Lubrication and lubricants), and ore flotation chemicals (see Mineral recovery and processing). Organophosphoms insecticides such as Parathion are made by chlorination of the appropriate diaLkyl dithiophosphate and subsequent reaction of the intermediate dialkyl thiophosphoric chloride with sodium -nitrophenolate according to the following (see... 

Dithiophosphates. These compounds (13) are made by reaction of an alcohol with phosphoms pentasulfide, then neutralization of the dithiophosphoric acid with a metal oxide. Like xanthates, dithiophosphates contain no nitrogen and do not generate nitrosamines during vulcanization. Dithiophosphates find use as high temperature accelerators for the sulfur vulcanization of ethylene—propylene—diene (EPDM) terpolymers. 

Ditluonsaure, /. dithiom c acid. Ditluophosphorsaure,/. dithiophosphoric acid. Ditiberjodsaure,/. diperiodic acid, diuretisch, a. diuretic. 

Table I outlines the major types of 1,1-dithiolato ligands. Table lA shows the related dithio acid complexes derived from dithiophosphinic, dithiocacodylic (dithioarsinic), dithioarsenate, and dithiophosphoric acids. The complexes most intensively studied to date are those of the dithiocarbamates and dithiophosphates.

When chlorine reacted with sodium diethyl dithiophosphate in the presence of an organic solvent, the desired compound was obtained in good yield. The reaction of phosphorus pentachloride on the sodium salt resulted in the same product. Thiophos-phoryl chloride is a probable by-product of this reaction. It was later found that diethyl dithiophosphoric acid could be chlorinated in an organic solvent without the intermediate preparation of the sodium salt. 

A general equation for the chlorination of certain dithiophosphoric acids and their salts can be written as follows ... 

Carboxylic acid, amine and O/7-dicihyl dithiophosphoric acid (3 equiv.) have been refluxed in toluene. This one-pot reaction yields the corresponding secondary or tertiary thioamides (Scheme ll).32... 

Numerous preparative methods have been reported for these acids and their salts and ester derivatives.1 4 Dithiophosphoric acids are accessible from the reaction of phosphorus pentasulfide with alcohols or phenols (Equation 18). Dithiophosphinic acids can be prepared from thiophosphinic chlorides and sodium hydrosulfide (Equation 19), although the phenyl derivative is better prepared using a modified Friedel-Crafts reaction in which phosphorus pentasulfide is reacted with benzene in the presence of anhydrous aluminium trichloride (Equation 20). 

Dithiophosphoric and dithiophosphinic acids are strong acids, with pKa values typically in the range 1-2 (in water or alcohol solutions).1 Dithiophosphinic acids are predominately thermally unstable compounds, and tend to undergo a condensation reaction with elimination of H2S on storage at room temperature (Equation 21). Although dithiophosphoric acids can also undergo a similar decomposition reaction, higher temperatures are usually required (>120°C). 

Dithiophosphoric acids, (RO)2PS2H, have been used for the thionation of carbonyl groups in certain aldehydes, ketones, amides, esters, thio-carboxylates and other organics.163 The mechanism for this reaction proceeds via a reversible nucleophilic attack of the thioacid on the carbonyl compound, which can then rearrange by way of a four-membered PSCO cyclic intermediate into the desired C=S containing molecule and thiophosphoric acid (Equation 81).163... 

Phosphor-1,1-dithiolates comprise ligands derived from dithiophosphoric acid 0,0-dithioesters (further called simply dithiophosphates), dithiophosphinic acids (dithiophosphinates), and the hybrid dithiophosphonic acid O-monoes-ters (dithiophosphonates) (Scheme 1). 

Diethyl dithiophosphoric acid, molecular formula, 5 713t... 

Dipyridone, see Diquat Disacryl, see Acrolein Disulfoton oxon sulfone, see Disulfoton Disulfoton oxon sulfoxide, see Disulfoton Disulfoton sulfone, see Disulfoton Disulfoton sulfoxide, see Disulfoton 2,2 -Dithiobis-ethanol, see Phorate Dithiophosphoric acid, see Phorate... 

The reductive cleavage of azo compounds is accomplished in good yields by catalytic hydrogenation [740, 747], with sodium hydrosulfite [255] and with 0,0-dialkyl dithiophosphoric acid (yields 23-93%) [748]. 

Metal complexes of dithiophosphoric acid, I, have found extensive application as oxidation inhibitors in various petroleum products. It is not surprising that many complexes are described in the patent literature 38-8 ) well as... 

Dithiophosphoric acids are readily prepared by the reaction When... 

Details of the preparations of numerous dithiophosphoric acids have been reported m,66,68,7o,79,84,8s,199-201,204-211) Ammonium, alkali and alkaline metal salts of the acids can be obtained by neutralization of the acids with hydroxides or carbonates 200,204,212-215) -phe sodium salts are probably best prepared by the procedure described by Makens, Vaughan and Chelberg... 

An alternate synthesis of dithiophosphoric acids, which is also applicable to the preparation of mixed acids f2, 3) 200,214,216,217) described by Malatesta 1 ), involves the reaction ... 

Oxidation of dithiophosphoric acids can give rise to a variety of products. The chlorination of dithiophosphoric acids gives rise to products such as (4), but other products can also be obtained. Oxidation of the acids or their salts with iodine yields bis- 0, 0 -dialkyldithiophosphoryl)disulfides,... 

R0)2P-S—S—P(0R)2. A number of these products and others from reactions of dithiophosphoric acids with oxidants are listed in Table 2 since they are some of the impurities to be anticipated. Thiophosphoryl (P=S) compounds are rapidly, quantitatively, and stereospecifically converted to phosphoryl (P=0) compounds by organic peroxy acids under mild conditions. The reactions of peroxy acids and dithiophosphoric acids and salts have apparently not been characterized. 

The preparation of metal dithiophosphate complexes usually involves the reaction of metal halides or acetates with dithiophosphoric acids or their salts. The metal complexes are generally purified by repeated fractional crystallization from halocarbon solvents such as chloroform. The reactions of mixtures of alcohols and alcohols and phenols with phosphorus(V) sulfide allegedly,... 

Reactions of dithiophosphoric acids and their salts with complexes are also employed to prepare dithiophosphate complexes, e.g.,... 

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