Cyano-compounds acidity

It has been stated that many halogen-free compounds, e.g., certain derivatives of pyridine and quinoline, purines, acid amides and cyano compounds, when ignited on copper oxide impart a green colour to the dame, presumably owing to the formation of volatile cuprous cyanide. The test is therefore not always trustworthy. The test is not given by duorides. 

Mild acid converts it to the product and ethanol. With the higher temperatures required of the cyano compound [1003-52-7] (15), the intermediate cycloadduct is converted direcdy to the product by elimination of waste hydrogen cyanide. Often the reactions are mn with neat Hquid reagents having an excess of alkene as solvent. Polar solvents such as sulfolane and /V-m ethyl -pyrrol i don e are claimed to be superior for reactions of the ethoxy compound with butenediol (53). Organic acids, phenols, maleic acid derivatives, and inorganic bases are suggested as catalysts (51,52,54,59,61,62) (Fig. 6). 

For a review of the acidity of cyano compounds, see Hibbert, F. in Patai Rappoport The Chemistry of Triple-bonded Functional Groups, pt. 1 Wiley NY, 1983, p. 699. 

See other cyano compounds endothermic compounds, organic acids... 

Appel, R. et al., Angew. Chem. (Intern. Ed.), 1983, 22, 785 Reaction with water is violent, forming triazinetricarboxylic acid. See Other ACYL HALIDES, CYANO COMPOUNDS... 

Vacuum distilled material kept dark for 6 months was found to have largely polymerised to a yellow solid, which exploded 15 days later [1], A bottle of uninhibited distilled material exploded after shelf storage for several months [2], It may be stored for several months out of contact with air under refrigeration. In contact with ambient air, it polymerises slowly, but rapidly in contact with acidic materials [3], See Other CYANO COMPOUNDS, POLYMERISATION INCIDENTS... 

Cyano-substituted selenophenes are valuable precursors of formyl derivatives.89 They are also used as starting materials for the preparation of carboxylic acids and their derivatives.128 By treating the cyano compounds with hydrogen selenide, selenoloamides (101) were obtained. As shown in... 

Dichloroanthaquinones have also been converted into the corresponding dicyano derivative, via what has been claimed to be the disulphonic acid (vide supra) [76]. Chloropurines have been converted into the corresponding cyano compounds using tetraethylammonium cyanide [77]. 

Methylenesulphones are more acidic than the simple esters, ketones and cyano compounds and are more reactive with haloalkanes [e.g. 48-57] to yield precursors for the synthesis of aldehydes [53], ketones [53], esters [54] and 1,4-diketones [55] (Scheme 6.4). The early extractive alkylation methods have been superseded by solidtliquid phase-transfer catalytic methods [e.g. 58] and, combined with microwave irradiation, the reaction times are reduced dramatically [59]. The reactions appear to be somewhat sensitive to steric hindrance, as the methylenesulphones tend to be unreactive towards secondary haloalkanes and it has been reported that iodomethylsulphones cannot be dialkylated [49], although mono- and di-chloromethylsulphones are alkylated with no difficulty [48, 60] and methylenesulphones react with dihaloalkanes to yield cycloalkyl sulphones (Table 6.5 and 6.6). When the ratio of dihaloalkane to methylene sulphone is greater than 0.5 1, open chain systems are produced [48, 49]. Vinyl sulphones are obtained from the base-catalysed elimination of the halogen acid from the products of the alkylation of halomethylenesulphones [48]. 

IH- 1,2,4-Benzotriazepines can be prepared in good yield by the reaction of some hydrazidoyl chlorides of type (461) with cyano compounds. The reaction is thought to proceed via the nitrilium salt (462). The products (463) are stable to alkali but are hydrolyzed in acid to give 1-phenyl-3R-indazoles (74T195). 

See Other CYANO COMPOUNDS, ENDOTHERMIC COMPOUNDS, ORGANIC ACIDS... 

Reacts violently with mineral acids, amines or inorganic bases, probably because of dehydration to acrylonitrile and subsequent catalysed polymerisation of the latter. See Other CYANO COMPOUNDS, POLYMERISATION INCIDENTS... 

See Sulfuric acid 2-Cyano-2-propanol See other CYANO COMPOUNDS... 

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