Sodium, Triphenylmethyl

Sodium triphenylmethane treatment of triphenylmethyl chloride with an excess of sodium in benzene leads, via the triphenylmethyl radical (Gomberg, 1900), to triphenylmethyl sodium ... 

The low degree of ionization in ether does not necessarily mean that triarylmethyl sodium compounds are largely covalent in that solvent. They may still be highly polar. Lithium iodide, for example, is also a poor conductor in ether although a good one in water. The conductivity of triphenylmethyl sodium in pyridine is very much... 

Triphenylmethyl sodium and triphenylmethyl potassium conduct in liquid ammonia although they slowly react with that solvent.887 888 When the liquid ammonia is allowed to evaporate from a solution of triphenylmethyl sodium in ammonia, the residue is a colorless mixture of sodamide and triphenylmethane. The sodium-tin and sodium-germanium compounds analogous to sodium triphenylmethide are also strong electrolytes in liquid ammonia. Sodium acetylide in liquid ammonia is dissociated to about the same extent as sodium acetate in water.889... 

Triphenylsilyl potassium adds like triphenylmethyl sodium to formaldehyde, giving the expected alcohol. 

The site of reaction on an unsaturated organometallic molecule is not restricted to the most probable position of the metallic atom or cation or to a position corresponding to any one resonance structure of the anion. This has been discussed in a previous section with reference to the special case of reaction with a proton. Although the multiple reactivity is particularly noticeable in the case of derivatives of carbonyl compounds, it is not entirely lacking even in the case of the derivatives of unsaturated hydrocarbons. Triphenylmethyl sodium reacts with triphenylsilyl chloride to give not only the substance related to hexaphenylethane but also a substance related to Chichi-babin s hydrocarbon.401 It will be recalled that both the triphenyl-carbonium ion and triphenylmethyl radical did the same sort of thing. 

Another differential reaction is copolymerization. An equi-molar mixture of styrene and methyl methacrylate gives copolymers of different composition depending on the initiator. The radical chains started by benzoyl peroxide are 51 % polystyrene, the cationic chains from stannic chloride or boron trifluoride etherate are 100% polystyrene, and the anionic chains from sodium or potassium are more than 99 % polymethyl methacrylate.444 The radicals attack either monomer indiscriminately, the carbanions prefer methyl methacrylate and the carbonium ions prefer styrene. As can be seen from the data of Table XIV, the reactivity of a radical varies considerably with its structure, and it is worth considering whether this variability would be enough to make a radical derived from sodium or potassium give 99 % polymethyl methacrylate.446 If so, the alkali metal intitiated polymerization would not need to be a carbanionic chain reaction. However, the polymer initiated by triphenylmethyl sodium is also about 99% polymethyl methacrylate, whereas tert-butyl peroxide and >-chlorobenzoyl peroxide give 49 to 51 % styrene in the initial polymer.445... 

Ph3CNa Triphenylmethyl sodium. s P-CH3C6H4SO3H p-Toluenesulfonic acid b CD ... 

McPhee, W. D., and E. G. Lindstrom The Reaction of Triphenylmethyl-sodium with Esters of a,jS-Unsaturated Acids. J. Amer. chem. Soc. 65,... 

Triphenylcarbinol, 811, 813, 814, 816 Triphenylchloromethane, 811, 815, 952 Triphenylguanidine, 643 Triphenylmethane, 509, 515 Triphenylmethyl sodium, 477,479 Triple point, 37, 38 Tri-n-propyl carbinol. 259 Trityl chloride, 815... 

A9(U)-Enol-l 1-acetates are formed by distillation of acetic anhydride in the presence of p-toluenesulphonic acid.122 Another procedure employed for the synthesis of enol benzoates involves treatment with benzoic anhydride and triphenylmethyl sodium or ethynyl sodium.11 Suitable procedures utilizing a diluent have been developed for the enol esterification of a 20-ketone without affecting an 11-ketone.12... 

Essentially covalent compounds such as the lithium alkyls. Derivatives of any alkali metal where charge delocalization can occur over several carbon atoms (e. g. triphenylmethyl-sodium, lithium-benzyl) were also considered to be largely ionic in constitution. 

Separate the ether solution of triphenylmethyl sodium as follows. Remove... 

If pure triphenylchloromethane and freshly prepared sodium amalgam are used, the yield of triphenylmethyl sodium should be almost quantitative and the concentration is usually 0.15 mol per litre (1). The reagent should be used as soon as possible after its preparation. 

Ethyl 2,2,4-trimethyl-3-oxopentanoate. Add 24 g (28 ml, 0.21 mol) of ethyl 2-methylpropanoate b.p. 110-111 °C, to the solution of c. 0.21 mol of triphenylmethyl sodium in approximately 1400 ml of ether contained in the 2-litre twonecked flask. Stopper the flask, shake well to effect complete mixing and keep at room temperature for 60 hours. Acidify the reaction mixture by adding, with shaking, 15 ml of glacial acetic acid, and then extract with 100 ml of water. Wash the ethereal solution with 50 ml portions of 10 per cent sodium carbonate solution until free from excess acid, dry over anhydrous sodium sulphate remove the ether under reduced pressure with a rotary evaporator. Distil the residue under reduced pressure through a short fractionating column. Collect the ethyl 2,2,4-trimethyl-3-oxopentanoate at 95-96 °C/ 18mmHg the yield is 14.5 g (74%). The b.p. at atmospheric pressure is 201-202 °C. 

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) ... 

A 1-Pyrroline V-oxides dimerize readily in alkaline media.335 Different products are obtained on treatment of 2,2-dimethyl-d1-pyrroline V-oxide with sodamide or triphenylmethyl sodium.338 Sodium-potassium alloy in ethylene glycol produces a derivative of 1, r-dihydroxy-2,2 -dipyrrolidyl.337... 

As you might expect, all the equilibria are now unfavourable, and this reaction does not go well under the normal equilibrating conditions (EtO- in EtOH), It can be made to go in reasonable yield if a stronger base is used, Traditionally, triphenylmethyl sodium is chosen. This is made from PhjCCl and sodium metal and is a very conjugated carbanion. 

This conclusion had to be revised when Piehl and Brown showed that although they were able to repeat Haller s work on the alkylation of phenylcyclopropyl ketone (199) by means of sodium amide and methyl iodide to give 200 (a reaction which they thought was wrong), unexpected reactions occurred in the case of ethyl cyclopropanecarboxylate (201). With sodium amide the amide (202), and with triphenylmethyl sodium the ketone (203) is formed. The latter reaction is normally typical of esters having no a-hydrogen atom ... 

Triphenylmethyl sodium /J-Ketocarboxylic acids from ketones s. 2, 750 —... 

Schonberg and his co-workers675 obtained sulfides by cleaving disulfides with organo-lithium or -sodium compounds e.g., he obtained phenyl tri-phenylmethyl sulfide from diphenyl disulfide and (triphenylmethyl)sodium. 

A third alkyl group can be introduced into a,a-dialkyl-substituted acetic esters by metallation with (triphenylmethyl)sodium or (triphenylmethyl)-potassium and subsequent treatment with an alkyl halide 406... 

Organolithium compounds, generally phenyl- or butyllithium, can be used, in the same way as(triphenylmethyl)sodium (see page 917), as base for C-alkyla-tion, since in certain cases they react by metal exchange with activated hydrocarbons. For instance, the 2-lithio derivative of resorcinol dimethyl ether is formed in 70% yield on reaction with phenyllithium. The organolithium compounds thus obtained react readily with alkyl halides or sulfates, forming a carbon-carbon bond 326 for example, 2,6-dimethoxytoluene is formed by... 

Dialkyl-substituted / -oxo esters are obtained free from monoalkylated products by acylating the sodio derivatives of, <%-dialkylated acetic esters, the latter being accessible as described above (page 917) from a disubstituted acetic ester and (triphenylmethyl)sodium.431... 

In the reaction with triphenylmethyl sodium the molecule of H3N3S2 certainly remains intact, since the isolation of the monosodium salt would otherwise be difficult to understand. It is still uncertain whether, in the reaction with potassium amide, the molecule is decomposed or remains intact that is, whether the potassium salt has the formula (XXIX) or (XXX) and (XXXI). 

Oxidation of the methylene group adjacent to the methoxycarbonyl group could be accomplished in low yield by treatment of the amino ester XXIa with sodio-p-nitrosomethylaniline and excess triphenylmethyl sodium followed by acid hydrolysis. This procedure gave rise to dl-vincamine XXII in low yield. Oxidation of isomer XXIb furnished products which could be differentiated from vincamine by thin-layer chromatography (see Chart IV). 

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