Sodium or potassium amide

Very strong bases such as sodium or potassium amide react readily with aryl halides even those without electron withdrawing substituents to give products corresponding to nucleophilic substitution of halide by the base... 

In the presence of a very strong base, such as an alkyllithium, sodium or potassium hydride, sodium or potassium amide, or LDA, 1,3-dicarbonyl compounds can be converted to their dianions by two sequential deprotonations.79 For example, reaction of benzoylacetone with sodium amide leads first to the enolate generated by deprotonation at the more acidic methylene group between the two carbonyl groups. A second equivalent of base deprotonates the benzyl methylene group to give a dienediolate. 

Diphenylcyclopropane has been prepared in 24% yield by the Simmons-Smith reaction,2 in 78% yield by treatment of 3,3-diphenylpropyltrimethylammonium iodide with sodium or potassium amide,3 in 61% yield by reaction of 1,1-diphenyl-ethylene with dimethylsulfonium methylide,4 and in unspecified yields from 1,1-diphenylethylene by reaction with diazomethane followed by pyrolysis of the resulting pyrazoline or by reaction with ethyl diazoacetate followed by distillation of the corresponding acid over calcium oxide.5... 

Animation of cellulose is a relatively new reaction (Scherer and Feildt [63]). It occurs if nitrocellulose in liquid ammonia is exposed to the action of sodium or potassium amide, according to the equation ... 

He was aware that termination reactions were of little importance, since successive additions of monomer could be made to polymerize after the complete reaction of the first added portion, even after the reaction mixture had been allowed to stand for some time. The relative efficiency of a group of initiators was also described. In the polymerization of butadiene, for instance, the deep red colour of cumylpotassium disappeared almost immediately, whereas with triphenylmethylsodium, the colour persisted during the polymerization process. With metallic sodium initiation, polymerization was shown to proceed at both ends of the polymer chain via an a,co-disodium adduct of the diene. It can be said, therefore, that by 1936 the essential characteristics of the process had been described, but interest in this topic was limited for many years afterwards. A few papers appeared in the literature. Beaman [6], in 1948, described the polymerization of methacrylonitrile and methylmethacrylate by sodium and triphenylmethylsodium in liquid ammonia, and similar experiments with styrene were described in 1949 [7, 8] using sodium or potassium amide as initiator. 

Cyclopropene itself is readily metalated by treatment with lithium, sodium or potassium amide in liquid ammonia. On standing, the solutions are slowly converted into mixtures of products containing two or three three-membered rings. ... 

The first direct evidence for the existence of anionic cr-adducts was presented by Zoltewicz and Helmick (72JA682). They identified anionic (T-adducts 18, 19, and 20 by the addition of pyrazine, pyrimidine, and pyr-idazine, respectively, to excess sodium or potassium amide in liquid ammonia. Identification was made possible by H-NMR spectroscopy. 

Shortly after the publication of the tr-adducts from diazines, Zoltewicz and co-workers reported the identification of anionic a-adducts from treating quinoline and isoquinoline with excess potassium amide in liquid ammonia. H-NMR studies showed that 1-amino-1,2-dihydroisoquinolinide (21) was formed with isoquinoline. In the case of quinoline, kinetic and thermodynamic products were observed. At — 45°C, adduct formation between quinoline and sodium or potassium amide in liquid ammonia, gave a mixture of 2-amino-l,2-dihydroquinolinide (22) and 4-amino-l,4-dihydroquinolinide (23), with the former compound being predominant. Warming the mixture resulted in irreversible conversion of 22 into the more stable 23. 

Quinoline easily forms a-adducts 22 and 23 in liquid ammonia containing excess sodium or potassium amide (Section II,A,3). The cr-adducts are time... 

For acylations with reactive esters, such as formate or oxalate (see Section 3.6.4.5), sodium alkoxides are still the bases of choice, but sodium hydride, dimsyl sodium, sodium or potassium amide or sodium metal have all been used for the in situ generation of the enolate anion. A typical example is shown in Scheme 47. Acylation by esters results in the production of 1 equiv. of the alkoxide ion, along with the p-dicarbonyl compound proton transfer then results in the production of the conjugate base of the dicarbonyl compound. This process normally leads to the more stable anion in the acylation of an unsymme-trical ketone. The acyl group thus becomes attached to the less-substituted a-position of the ketone. The less stable 0-acylated products are normally not observed in such reversible base-catalyzed reactions. Methyl alkyl ketones are normally acylated on the methyl group where both a-carbons are substituted to the same extent, acylation occurs at the less-hindered site. Acylation is observed only rarely at a methine carbon as the more stable p-diketone enolate cannot be formed. 

Chlorothen. N-((S-Chloro-2-thienyl)methyl]-iV.AC-dimethyl-N-2-py ridinyl-lt2-ethanediamine 2-/(5-chloro-2-thenylH2-dimethylaminoethyl)amino]pyridine N. W-dimethyl -AT -(2 -py ridyl) -N -(5 -chloro -2 -thenyDeth -ylenediamine N,N-dimethy -N -(a-pyridyl)-N -(2-methyl-5-chlorothienyl)ethylenediamine iV-5-chtoro-2-thienyl-methyl-Ai AT -dimethyl -N-2-pyridylethylenediamine chlo-ropyrilene chloromethapyrilene chlorothcnylpyramine. C H,8C]N3S mo] wt 295.85. C 56.84%, H 6.13%, O 11.98%, N 14.20%, S 10.84%. Prepd by the condensation of 5-cNoro-2-theny] chloride and N,JV-dimethyl-JV -(2-pyrid-ylkthylenediamine in the presence of sodium or potassium amide Clapp et at., J. Am. Chem. Soc. 69, 1549 (1947). 

For the removal of the proton at the a-carbon atom, besides alkaline hydroxides or alcoholates in lower alcohols (methanol or ethanol), sodium or potassium amide in liquid ammonia, diethyl ether, toluene or benzene, sodium hydride in a toluene-THF mixture, or aluminium tri-r-butoxide in benzene have been used as bases. Aldol condensations have been performed over a temperature range between -33°C and around 100°C. The reaction times can vary from some minutes to several days. The yields of the aldol condensation reactions are enhanced by applying a large excess of the ketone. This can even lead to complete replacement of any other solvent by the keto compound. 

Diketones behave similarly to (3-keto esters. Sodium or potassium amide in liquid ammonia is a suitable base/solvent system in this case. 

Reaction of cyclopropane with sodium or potassium amides in liquid ammonia results in the loss of a vinylic proton rather than a methylene proton [198,199] similarly methyl cyclopropene-1--carboxylate exchanges its vinylic but not its methylene proton in base [200]. The structure of the cyclopropenide anion is clearly shown by its H-n.m.r. spectrum. In the case of the sodium salt this is as follows 56.73 (t,lH), -0.45 (d,2H), J = 1.94 Hz [199]. These compounds dimerise on steuiding with alkyl halides they give mono- and di-alkyl cyclopropenes [199] ... 

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