Hofmann degradation carboxylic acid amide

Urethans from carboxylic acid amides Hofmann degradation CONHs —> NHCOOP... 

Sodium hypochlorite Hofmann degradation of carboxylic acid amides... 

Hofmann degradation of carboxylic acid amides with loss of 1 G-atom s. 17, 337... 

Methyl-3,3 -bipyridine has been oxidized by permanganate to 3,3 -bi-pyridine-4-carboxylic acid. " 3,3 -Bipyridine carboxylic acids are easily decarboxylated and have been esterified and converted to amides, hydrazides, and acylazides. The Hofmann degradation, of the diamide of 3,3 -bipyridine-2,2 -dicarboxylic acid affords the expected 2,2 -diamino-3,3 -bipyridine, but some of the tricyclic system 108 is formed as well. A 2,2 -bis(acylazide) is converted to a similar tricyclic system with ethanol via the intermediate isocyanate, and several related reactions have been described. The simultaneous dehydration... 

Amines have been prepared on insoluble supports by Hofmann degradation of amides [222] followed by hydrolysis of the intermediate isocyanates (Figure 10.5). One reagent suitable for this purpose is [bis(trifluoroacetoxy)iodo]benzene, which can be used both on cross-linked polystyrene [223] and on more hydrophilic supports such as polyacrylamides (Figure 10.6). Support-bound carboxylic acids can also be degraded via the acyl azides (Curtius degradation [224,225]) to yield isocyanates. 

A number of methods involve the rearrangement of carboxylic acid derivatives via nitrenes. The best known of these is the Hofmann degradation of amides. This involves treating an amide with bromine and alkali. The A-bromo compound undergoes an a-elimination in the presence... 

Phenyleyclopentylamine has also been prepared from 1-phenylcyclopentanecarboxylic acid by means of the Hofmann degradation of the intermediate amide and from the intermediate carboxylic acid chloride by the Curtins reaction. In the method described, using the mixed carboxylic-carbonic anhydride, improved yields of the amine are obtained. 

In general, hydrazides may be prepared by many of the methods analogous to those used in the preparation of amides. For example, hydrazine salts of carboxylic acids and reactions of hydrazine with esters, acyl halides, acyl anhydrides, and amides may be used to produce hydrazides. A reaction analogous to the Hofmann degradation is the formation of hydrazides from ureides (acylureas) [54] (Eq. 4). 

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