Phenylsodium

A mixture of 150 ml. of toluene, 11.5 g. (0.5 gram atom) of sodium sand, and 22.5 g. (0.2 mole) of chlorobenzene is stirred at room temperature under an atmosphere of dry nitrogen. After about 45 minutes an exothermic reaction sets in, and the temperature of the reaction mixture is held below 40° with a cooling bath. The entire reaction requires about 2 hours. The toluene solution of phenylsodium should be used immediately. (See preparation of benzylsodium, p. 32.) The yield of organometallic compound is 87%. The yield is determined from the amount of benzoic acid obtained after pouring the above solution on excess crushed solid carbon dioxide followed by acidification. 

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The fact that n-butylbenzene can be prepared in reasonable yield by the action of sodium upon a mixture of bromohenzene and n-butyl bromide can be partly explained on the assumption that n-butyl bromide reacts with phenyl-sodium more rapidly than does bromobenzene. It is interesting to note that n-butylbenzene can be prepared either from benzylsodium and n-propyl bromide or from phenylsodium and n-butyl bromide (Section VI,29). 

Suspensions containing phenylsodium may ignite and burn violently in moist air. See Sodium Halocarbons (reference 8)... 

The sonochemistry of the other alkali metals is less explored. The use of ultrasound to produce colloidal Na has early origins and was found to greatly facilitate the production of the radical anion salt of 5,6-benzo-quinoline (225) and to give higher yields with greater control in the synthesis of phenylsodium (226). In addition, the use of an ultrasonic cleaning bath to promote the formation of other aromatic radical anions from chunk Na in undried solvents has been reported (227). Luche has recently studied the ultrasonic dispersion of potassium in toluene or xylene and its use for the cyclization of a, o-difunctionalized alkanes and for other reactions (228). 

Triphenylcarbinol has been obtained by the reaction between phenylmagnesium bromide and benzophenone,1 methyl benzoate, or phosgene 8 by action of phenylsodium upon benzophenone, benzoyl chloride, ethyl chlorocarbonate, or ethyl benzoate 4 by hydrolysis of triphenylchloromethane 5 and by oxidation of tri-phenylmethane.6... 

In a study of reaction of phenylsodium with benzene, Morton and Lanpher (4S) found that at lower temperatures the adduct was stabilized by trans-metalation with another molecule of phenylsodium, yielding a dianion [Reaction (29)]. 

Phenyllithium, 2259 Phenylsodium, 2287 Phosphoryl dichloride isocyanate, 0327 Phthalic anhydride, 2899 2-Piperidone, 1934 Platinum diarsenide, 0107 Poly(butadiyne), 1386 Poly(carbon monofluoride), 0337 Poly(ethylene terephthalate), 3262 Poly(selenium nitride), 4730... 

Similar reactions of ferrocene with phenylsodium or n-amylsodium lead to the corresponding sodiated products (XXXI, XXXII, M = Na) (59, 60). The steric course of both metalation reactions has been studied, and it has been proved that dimetalation occurs in opposite cyclopentadienyl rings (28). 

Phenylsodium is formed initially in the reaction between benzonitrile and sodium (Scheme 79) (59JOC208). Trimerizations of aryl or heterocyclic nitriles catalyzed by amines or alkoxides resemble the reactions of the perfluoronitriles described above (Schemes 77 and 78 respectively). Kurabayashi et al. (71BCJ3413) studied the trimerization of benzonitrile under pressure in methanol, and have shown that the rate determining step is the reaction of the benzimino ether with benzonitrile. Steric factors exert an important influence in the trimerizations of aryl cyanides. The cyclizations of ort/zo-substituted aryl cyanides need more severe conditions than either the corresponding meta or para derivatives (Table 14). 

A series of 2-azaallyl derivatives have also been made. The reaction between dibenzylamine and phenylsodium gave a red precipitate of diben-zylamidosodium that dissolved in PMDTA/toluene to give a much darker solution from which red-green dichroic crystals were isolated. These were shown to consist of the azaallyl compound NafPhCHNCHPh]. PMDTA,... 

Cyano and alkoxycarbonyl groups are favorable in this respect and propeneni-trile and methyl 2-methylpropenoate can be polymerized with sodium amide in liquid ammonia. Ethenylbenzene and 2-methyl-1,3-butadiene undergo anionic polymerization under the influence of organolithium and organosodium compounds, such as butyllithium and phenylsodium. 

Better yields of alkylbenzenes result if the arylsodium is first prepared and then subjected to a suitable alkylation reaction. In the preparative example of butylbenzene (Expt 6.1), benzylsodium is conveniently obtained by first forming phenylsodium by reaction between sodium and chlorobenzene in a toluene medium, and then heating the toluene suspension of the phenylsodium at 105 °C for about 35 minutes when a transmetalation process occurs (formulated at the beginning of Expt 6.1). 

On the small scale, no reaction occurred on boiling perfluorohexyl iodide in contact with metallic sodium. With 140 g of iodide and 7 g of sodium an explosion occurred after 30 min [6]. The temperature range for smooth interaction of bromobenzene, 1-bromobutane and sodium in ether to give butylbenzene is critical. Below 15°C reaction is delayed but later becomes vigorous, and above 30°C the reaction becomes violent [7]. Sodium wire and chlorobenzene react exothermally in benzene under nitrogen to give phenylsodium, and the reaction must be controlled by cooling. Use of... 

Both phenyllithium and butyllithium reacted with tetraacetyl-glucosyl bromide to yield products identical with those previously obtained with the corresponding Grignard reagents. Benzyllithium or lithium acetylide with tetraacetylglucosyl bromide resulted in intractable sirups or tars. Sodium acetylide and phenylsodium likewise led to no crystalline product. 

Hydroxide and alkoxide anions are strong enough bases to promote a elimination from chloroform, and from other trihalomethanes. Carbenes can be formed from dihaloalkanes by deprotonation with stronger bases such as LDA, and even from primary alkyl chlorides using the extremely powerful bases phenylsodium or f-BuLi/f-BuOK (weaker bases just cause P elimination). 

The synthesis of pure bis(phenylsodium)nickel-ethylene (13) is achieved by reaction of a mixture of NaC6H5/LiC6H5 (Na/Li = 2-4 1) with CDTNi(O) (1) in the molar ratio (NaC6H5 + LiC Hs)/Ni = 2 1 in the presence of ethylene (79). The phenyllithium-containing nickel-ethylene complex 9 remains dissolved while the bis(phenylsodium)nickel-ethylene (13) precipitates out as an orange-red powder. 

An electropositive metal in organic compounds of alkali metals is replaced by a more electropositive one in series of reversible reactions. More electronegative, i. e. more acid, hydrocarbon groups or whole molecules replace those which are less acid [140]. Caesium replaces lithium in ethyllithium. Benzene, which is a stronger acid than ethane, replaces ethyl in ethyllithium. Toluene and H2 are more acid than benzene, and they can therefore replace phenyl in phenylsodium [141, 142],... 

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