Triphenyl lead chloride

Similar reactions with tetramethyl lead, hexaphcnyl dilead, and triphenyl lead chloride yield aryl organo tellurium dichlorides4,5. 

Hexaphenyl dilead, tetramethyl lead, and triphenyl lead chloride" donate phenyl groups to aryl tellurium trichlorides to produce aryl phenyl tellurium dichlorides in yields from 73 to 92%. The lead compounds are more reactive than the tin and silicon derivatives and even react at 20°. 

Organolead tri-iodides have been prepared from Pbl and an alkyl iodide in the presence of MegSb as catalyst. They are low melting yellow-orange solids and the Pb—C bond is stable to protic reagents. Triphenyl-lead chloride and bromide both possess a five-co-ordinate bridged structure. ... 

CisHisClPb Triphenyl-lead chloride Pb, (sp % 2.170—2.210(10), trigonal bipyramidal 319... 

To enhance the applicability of UV spectrophotometry in pharmaceutical steroid analysis by increasing its selectivity and sensitivity, various methods have been developed based on chemical reactions leading to colored derivatives. Although their importance has decreased considerably, some of these methods are still in use in pharmacopoeias, mainly in the assay of formulations. For example, the A" -3-oxo and A " -3-oxo steroids can be determined as iso-nicotinoyl hydrazones (/Uax 380 and 410 nm 11500 and 17000, respectively). The dihydroxy-acetone side chain of corticosteroids at C17 reduces tetrazolium reagents to colored formazans (Amax 485 and 525 nm with triphenyl tetrazolium chloride and Tetrazolium Blue reagents, respectively e 16000 and 24000), thus creating the basis for a stability-indicating indirect colorimetric assay. Corticosteroids... 

Addition of benzoyl chloride to 2.5-dimethyl-3,4,6-triphenyl-3//-azepine (13) in benzene in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) leads to elimination of hydrogen chloride and formation of the 2-methylene-l//-azcpine 14.117 All attempts to isomerize the methylene derivative to 1-benzoyl-2,5-dimethyl-3,4,6-triphenyl-l//-azepine under basic conditions failed. Analogous reactions can occur with 2,5-dielhyl-3,4,6-triphenyl-3//-azepine. 

In an attempt to demonstrate the existence of pentavalent nitrogen, Schlenk and Holtz studied the reaction of triphenylmethyl sodium with tetramethylammonium chloride (52). The highly colored material was strongly conducting in polar solvents and could be identified as a salt, the stability of which is due to the resonance stabilization of the triphenyl-methide anion. In the absence of such stabilizing substituent effects (53), as with n-butyl or another alkyllithium reagent, a metalation of the tetramethylammonium cation occurs, which leads to type I products (18) ... 

The compounds are prepared in a similar manner to tlie corresponding derivatives of lead, the starting-point being tin triphenyl chloride, but the yields in this case are practically quantitative. ... 

Lead triphenyl chloride.—When the precipitate obtained by shaking lead triphenyl iodide with alcoholic caustic alkali is treated with 50 per cent, aqueous hydrochloric acid, a quantitative yield of the above chloride is produced. This crystallises from alcohol in snow-white needles, which sinter at 204° C. and melt at 206° C. It has the same solubility as the bromide. 

Lead triphenyl iodide. —If the mother-liquors of the above bromide be treated with potassium iodide, and the product obtained crystallised from water, the iodide separates in pale yellow prisms, which sinter at 189 C. and melt sharply at 142 C. to a canary yellow liquid, which soon deposits lead iodide. It is difficultly soluble in liot methyl alcohol, and insoluble in water, and is distinguished from all the other lead aryl or alkyl iodides by its stability. It does not appear to yield an oxide with alcoholic sodium or potassium hydroxide, but a white precipitate is thrown down, this yielding lead triphenyl chloride with 50 per cent, hydrochloric acid. 

Lead triphenyl sulphide is obtained as a white, ffocculent precipitate by passing hydrogen sulphide into a concentrated alcoholic solution of the chloride. When freshly made it is remarkably soluble in organic solvents, and stable on heating. It is easily soluble in alcohol or ammonium sulphide, but not appreciably in water. 

Metathesis of triarylbismuth dichloride with a variety of metal salts such as fluoride, azide, cyanide, carboxylates and sulfonates has been used frequently for the synthesis of triarylbismuth(V) compounds of the type Ar Bi Y 2, where Y is the corresponding anionic group (Section 3.1.1). The reaction of triphenyl-bismuth dichloride with mercuric chloride in an alkaline medium leads to triphenylbismuthine, while treatment of triphenylbismuth dicyanide with mercuric oxide results in the formation of triphenylbismuthine oxide (Section... 

A related group of compounds is that of the gold(III) dimethyl(alkoxycarbonyl) complexes, accessible by the reaction of carbon monoxide with dimethyl(alkoxy)(triphenyl-phosphine)gold(III), which is prepared in situ from cw-[AuIMe2(PPli3)] and sodium alkoxide in methanol (equation 80)353,359. Thermolysis of the methoxycarbonyl complex in benzene leads to the reductive elimination of methyl acetate and ethane, indicating competition between the two modes of decomposition illustrated in Scheme 27. The reaction of the same complex with electrophiles such as hydrogen chloride proceeds with liberation of carbon monoxide and methanol, as illustrated in equation 81. 

Preparation. A simple route to this reagent is by reaction of 1,4-dichloro-2-butyne x ith Bu SnLi. Note that coupling of l,3-butadien-2-ylmagnesium chloride with Ph,SnCl leads to the triphenyl analogue but the coupling with BujSnCl proceeds without skeletal -hange. 

In the simplest form of the Abramov reaction, the phosphorus-containing reactant is hypophosphorous acid (phosphinic acid) or an ester thereof, and in the reactions between the acid and formaldehyde or benzaldehyde the initial product is the phosphinic acid 144 (R = H or Ph.). However, the reaction can proceed further to give the bis(l-hydroxyalkyl)phosphinic acid (145 R = H or Ph) the latter (R = Ph) reacts readily with yet more benzaldehyde to give its benzylidene derivative, 5-hydroxy-2,4,6-triphenyl-1,3,5-dioxaphosphorinane 5-oxide (146 R = Ph). When acted on by a second mole of cyclohexanone in the presence of acetyl chloride, (l-hydroxycyclohexyl)phosphinic acid (147) gives the novel phosphinic chloride 148, characterized as the free acid 149 following ready hydrolysis A reaction between a phosphinic acid (150) and a second (non-identical) carbonyl compound leads to an unsymmetrical phosphinic acid (151). Esters of symmetrical 1, r-dihydroxy-substituted phosphinic acids are preparable from hypophosphite esters, H2P(0)0R ". ... 

In order that the esterification may go to completion, the water that is formed must be eliminated, but before it can escape, it must diffuse to the surface, which, in a large commercial batch, may involve considerable travel. Diffusion is slow in these mixtures which are Mrly viscous at the start and become much more so toward the end. The operations are commonly carried on at relatively high temperatures, 200-300 C, at which the viscosities are considerably reduced but are still high. At these temperatures, sulfuric acid and like catalysts, which are so efficient at lower temperatures, cannot be used. A wide variety of catalysts, such as lead, calcium, zinc, phosphoric acid, zinc chloride, triphenyl phosphite, and p-toluenesulfonic acid, have been used. 

OXIDATION, REAGENTS Acetyl nitrate. Bis(tri-n-butyltin)oxide. Bromine-Hexameth-ylphosphoric triamide. f-Butyl perbenzoate. Ceric ammonium nitrate. N-chlorosuc-cinimide-Dimethyl sulfide. Chromic add. Chromic anhydride. Chromic anhydride-Acetic anhydride. Chromic anhydride-Hexamethylphosphoric triamide. 2,3-Dichloro-5,6-dicyano-l,4-benzoquinone. Dimethyl sulfoxide. Dimethyl sulfoxide-Trifluoro-acetic anhydride. Diphenylseleninlc anhydride. Iodine tris(trifluoroacetate). Lead tetraacetate. N-Methylmorpholine -N-oxide. p-NitrobenzenesulfonyI peroxide. Oxygen, singlet. Palladlumfll) chloride. Peroxybcnzimidic acid. Phenylseleninyl chloride. N-Phenyl-l,2,4-triazoline-3,5-dione. Potassium chromate. Potassium superoxide. Pyri-dinium chlorodiromate. Salcomine. Silver carbonate-Celite. Sodium hypochlorite. Sulfuryl chloridc-Silica gel. Thallium(III) acetate. ThaUium(III) nitrate. Triphenyl phosphite ozonide. Trltyl tetrafluoroborate. Uranium hexafluoride. 

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