Aliphatic -2-hydroxyamides

In addition, a fluid loss additive for oil-based drilling fluids, which consists of fatty acid compounds and lignite or humic acid, an oil-soluble or oil-dispersible amine or amine salt with phosphorie acid, or an aliphatic amide or hydroxyamide [392], has been described. 

Aromatic or conjugated aldehydes react in excellent yields, whereas the reaction with aliphatic aldehydes requires longer times and leads to A-hydroxyamides in lower, althongh satisfactory, yield. When both aldehyde and ketone gronps are present on the same... 

Reaction with ammonia and primary and secondary amines can also give two types of products, 0-hydroxyamides or amino acids (equation 49). The amide is obtained from the reaction of 0-propiolactone with ammonia in water, while the amino acid is obtained from the reaction in acetonitrile, both in good yield. 0-Lactones react very generally with both aliphatic and aromatic amines, but the type of product does not correlate with polarity of solvent or basicity of amine. Fortunately, conditions can usually be found for the formation of the desired product. 

Concellon, J. M. Bardales, E. The first transformation of aliphatic a,/1-epoxyamides into a-hydroxyamides. Org. Lett. 2003, 5, 4783-4785. 

Isonitriles can be used for a few useful synthetic transformations. The Passerini reaction is a convenient route to amide esters. When propionic acid was heated with acetone and fcrt-butylisonitrile, for example, the product was a-propanoyloxy amide 9. A useful modification of the Passerini reaction used trifluoroacetic acid rather than a normal aliphatic carboxylic acid. When a-phenoxyacetaldehyde (10) reacted with fcrf-butylisonitrile and trifluoroacetic acid (TFA), 11 was formed. Hydrolysis of this trifluoroacetyl ester with aqueous sodium carbonate led to isolation of the a-hydroxyamide (12) in 69% yield. This modification has the advantage that hydrolysis conditions for trifluoroacetate esters are milder than for normal esters. 

Another bienzymatic cascade was designed to synthesize amides instead of acids. Aliphatic (S)-2-hydroxyamides are produced from the corresponding aldehyde and HCN (Figure 11.14). The cascade employs MeHnL and the relatively stable NHase... 

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