A-Keto nitriles

Acid derivatives that can be converted to amides include thiol acids (RCOSH), thiol esters (RCOSR), ° acyloxyboranes [RCOB(OR )2]. silicic esters [(RCOO)4Si], 1,1,1-trihalo ketones (RCOCXa), a-keto nitriles, acyl azides, and non-enolizable ketones (see the Haller-Bauer reaction 12-31). A polymer-bound acyl derivative was converted to an amide using tributylvinyl tin, trifluoroacetic acid, AsPh3, and a palladium catalyst. The source of amine in this reaction was the polymer itself, which was an amide resin. 

RuCl2(CO)3]j The oxidative dehydrogenation of a-hydroxy esters RCH(OH) COOR and cyanohydrins RCH(OH)(CN) to the corresponding a-keto esters and a-keto nitriles was effected by [RuCl3(CO)3]3/TBHP/CgHg, and the reaction was also catalysed by RuBrj, Ru(acac)3, RuClj(PPh3)3 and Ru3(CO)j2 [695],... 

Acid derivatives that can be converted to amides include thiol acids RCOSH, thiol esters RCOSR,911 acyloxyboranes RCOB(OR )2,912 silicic esters (RCOO)4Si, 1,1,1-trihalo ketones RCOCX3,913 a-keto nitriles, acyl azides, and nonenolizable ketones (see the Haller-Bauer reaction 2-33). 

Cyclisation of a keto nitrile in presence of a halogen and an acid leads to an amino furanone... 

During thermolysis diacylfuroxans are transformed into the /V-oxides of a-keto nitriles, which form cyclic adducts in situ with various dipolarophiles [525], This method was used for the production of 4-nitro-3-(2-acetoxybomyl-2-carbonyl) isoxazole (yield 50%) by boiling bis(2-acetoxybomyl-2-carbonyl)furoxan with an excess of trans-/)-dimethylammonitroethene in toluene (Scheme 84). 

The conversion of aliphatic and aromatic acyl halides to a keto nitriles has been effected by heating the halides with dry metallic cyanides, of which cuprous cyanide has given the most satisfactory results (60-87%). The acyl bromides rather than the chlorides ate preferred, at least in the formation of aliphatic compounds. Thus, pyruvonitrile is prepared in 77% yield from acetyl bromide and cuprous cyanide whereas no product is obtained if acetyl chloride is employed. Benzoyl cyanide is made in 65% yield by heating the corresponding acyl chloride with cuprous cyanide. "... 

A somewhat similar oxidation takes place when an aldehyde is treated with sodium cyanide and manganese dioxide or argentic oxide [382], The reaction is assumed to proceed through a cyanohydrin, which is oxidized to an a-keto nitrile. The a-keto nitrile in turn is converted into an acid (by argentic oxide in methanol) or an ester (by manganese dioxide in methanol). The method is especially suited for a, -unsaturated aldehydes [382] (equation 354). 

A special route from imidates to ( -ethyl arenecarbothioates via 0 -acetals of a-keto nitriles as intermediates is also suitable for the preparation of nitro derivatives which are difficult to obtain in good yields by other methods (equation 53). ... 

The addition of the Sodio-derivative of ethyl acetoacetate, ethyl malonate, or ethyl cyano acetate to an olefine function that is specifically activated by a keto, nitrile or O... 

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