Solvent carboxylic acid route

The potential of the microwave-enhanced decarboxylation route in the radioactive waste area is immediately apparent - washing the tritium waste with a protic solvent leads to exchange of the labile tritium. The solvent can then be used with one of the carboxylic acids mentioned above and after the microwave-enhanced decarboxylation the waste is now in the form of a solid (greatly reduced volume) which may have some further use. 

Solutions of nitric acid in chlorinated solvents can add to some alkenes to give nitrate esters. Some tertiary nitrate esters can be prepared in this way isobutylene (49) reacts with fuming nitric acid of 98.6 % concentration in methylene chloride to give ferf-butyl nitrate (50). However, the products obtained depend on both the substrate and the reaction conditions /3-nitro-nitrate esters, vic-dinitrate esters, /3-nitroalcohols and nitroalkenes have been reported as products with other alkenes. Oxidation products like carboxylic acids are also common, especially at elevated temperatures and in the presence of oxygen. The reaction of alkenes with fuming nitric acid is an important route to unsaturated nitrosteroids, which assumedly arise from the dehydration of /3-nitroalcohols or the elimination of nitric acid from /3-nitro-nitrate... 

Subsequently, it was shown that the reaction was catalyzed by base (48M(79)106). Dicyandiamide reacts with nitriles (the most valuable method), amidines, cyanamides, ammonia, cyanates, thiocyanates, carboxylic acids and anhydrides to yield 1,3,5-triazines (Table 13). This synthetic route has been reviewed thoroughly several times (59HC(13)1, p. 219,61MI22000, p. 650, 73ZC408). The base-catalyzed reaction of dicyandiamide with alkyl or aryl nitriles (Scheme 65) proceeds via the imino ether anion and the rate determining step is solvent dependent. In DMSO the formation of the imino ether is rate determining, but in 2-methoxyethanol the reaction between the anion and dicyandiamide controls the rate (66T157). 

The acyloxymercuration-demercuration of alkenes provides an alternative route to esters which is probably less prone to caibon skeleton rearrangements than the direct addition of carboxylic acids to alkenes (equation 282). This reaction has recently been reviewed.477 The reaction is most commonly run using mercury(II) acetate in acetic acid, though other mercury salts may be used and aprotic solvents can also be employed. Equilibria have been measured for the reaction of mercury(II) trifluoroacetate and alkenes in tetrahydrofuran, and were found to be solvent dependent.478... 

The solvent and temperature effect on the 71-route cyclization of endo-bicyclo[3.3.1]-non-6-ene-3-carboxylic acid (24) has been studied.40... 

Acylation of a-lithio-a-phosphonylalkyl sulfides (440) with carboxylic acid esters was utilized as a facile route to a-alkylsulfenyl substituted p-ketophos-phonates (441). Keto-enol tautomerism of these new compounds in different solvents as well as regiochemistry of alkylation and acylation reactions and usefulness for HWE olefination reactions were studied (Scheme 104). ... 

The transformation of alkyl halides with cyanides (equation 1) represents not only the classical route to nitriles, but, if modified properly, is still of very great practical importance even today. A whole series of review articles stress the scope and value of this reaction. Although the substituent R may be varied to a large extent, the primary as well as the benzylic halides generally give higher yields than secondary and tertiary ones, as, with the latter, the formation of alkenes gains in importance. This side reaction as well as the undesired formation of alcohols and ethers, which sometimes takes place in aqueous media or with alcohols as solvent, is of course due to the basicity of the cyanide ion. Under deleterious conditions one may even observe carboxylic acids, which result fi-om the hydrolysis of the nitriles. - Some of these undesired side reactions may be avoided by the use of CuCN instead of sodium or potassium cyanide. ... 

Aminoanthraquinones undergo acylation with acid chlorides, generally in organic solvent, and with carboxylic acids or anhydrides in oleum. Benzoylation is an important reaction, since many vat dyes contain benzamido groups in the a- (1-) position. The free amino groups may be diazotized to afford biaryl compounds. The great lability of substituents in anthraquinones, as compared with similar benzene and naphthalene compounds, offers a number of routes to aminoanthraquinones. 

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