Isobutyric acid amide

Treatment of FMC 55626 with triethylamine (Scheme 3) resulted in gas evolution, presumably carbon dioxide, and formation of complex reaction products. Although the components of this reaction have not been identified, the NMR spectrum did show a peak that could be assigned to the methine proton of an isobutyric acid. In the case of two primary amines (methylamine and aniline), cleavage of the acyl oxygen bond occurred to give the bis-amides 7. These amides are similar in activity to FMC 55626 and, like FMC 55626, are several times more active in autoclaved soils. 

Dimethylacetic acid. See Isobutyric acid Dimethylacetone. See Diethyl ketone Dimethyl acetone amide. See Dimethyl acetamide... 

The replacement of a nitrile with a carboxylic acid group is the least detrimental transformation, and is an example of an atypical bioisosteric replacement. Moreover, there are a few others that add polarity to the molecule, such as methyl to methyl amide, addition of a isobutyric acid, 1,2-phenyl to 2,3-pyridine, and 2,3-pyridine to 2,3-pyrazine groups. Interestingly, the substitution of a methyl with an exotic trifluoromethyl ether moiety [34] is bioisosteric, even though there is a considerable increase in lipophilidty. This is also the case for the replacement of the more metabolically labile isopropyl ether with the cydopropyl group. Finally, a little considered bioisosteric transformation is 2-thiophene to para-fluorophenyl, which has been very recently proposed in a large-scale MMP analysis [35]. 

Eq. 25) [295]. A similar mechanism has also been proposed for the electrolysis of isobutyric and pivalib acid in acetonitrile [296]. As the intermediate alkyl cation can rearrange and the intermediate iminium cation can furthermore react with the starting carboxylic acid three different amides can be isolated (Eq. 26) [295 a]. The portion of the diacylamide can be considerably increased if the electrolyte consists of acetonitrile/ acetic acid [295 b]. 

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