Amidation of Alcohols

A new and convenient method was found for the one-pot synthesis of symmetrical and unsymmetrical linear imides in the presence of SSA. The amidation of alcohols with nitriles in the presence of an acidic catalyst is known as the Ritter reaction. Salehi et al. have modified this method and developed the one-pot synthesis of a wide variety of linear imides instead of alcohols [97] (Scheme 5.17). 

Scheme 26 Proposed mechanism for the dehydrogenative amidation of alcohols with azides...

Arefi M, Saberi D, Karimi M, Heydari A (2015) Superparamagnetic Fe(OH)3 Fe304 nanopartieles an efBcient and reeoverable eatalyst for tandem oxidative amidation of alcohols with amine hydrochloride salts. ACS Combin Sci 17(6) 341-347... 

Scheme 8.12 Proposed catalytic cycles for the ruthenium-catalyzed amidation of alcohols.

Overall, the experimental and theoretical results do not match perfectly, but the experimental evidence is stUl able to sufficiently validate the computational results. This study provides insight into the mechanism of the ruthenium-catalyzed oxidative amidation of alcohols that may, as the authors suggest, be used to perform in silico ligand studies in the future. 

C2H4N2O3, NH2CONHCOOH. Unknown in the free state as it breaks down immediately to urea and COi- The NH4, Ba, Ca, K and Na salts are known and are prepared by treating ethyl allophanate with the appropriate hydroxide. The esters with alcohols and phenols are crystalline solids, sparingly soluble in water and alcohol. They are formed by passing cyanic acid into alcohols or a solution of an alcohol or phenol in benzene. The amide of allophanic acid is biuret. Alcohols are sometimes isolated and identified by means of their allophanates. 

Section 15 11 Oxidation of alcohols to aldehydes and ketones is a common biological reaction Most require a coenzyme such as the oxidized form of nicotin amide adenine dmucleotide (NAD" )... 

Catalytic vinylation has been appHed to a wide range of alcohols, phenols, thiols, carboxyUc acids, and certain amines and amides. Vinyl acetate is no longer prepared this way in the United States, although some minor vinyl esters such as stearates may still be prepared this way. However, the manufacture of vinyl-pyrrohdinone and vinyl ethers still depends on acetylene. 

Many of these reactions are reversible, and for the stronger nucleophiles they usually proceed the fastest. Typical examples are the addition of ammonia, amines, phosphines, and bisulfite. Alkaline conditions permit the addition of mercaptans, sulfides, ketones, nitroalkanes, and alcohols to acrylamide. Good examples of alcohol reactions are those involving polymeric alcohols such as poly(vinyl alcohol), cellulose, and starch. The alkaline conditions employed with these reactions result in partial hydrolysis of the amide, yielding mixed carbamojdethyl and carboxyethyl products. 

Defoamers (qv) are available in several forms, composed of many different materials. Historically, paste and soHd defoamers were used extensively. Composed of fatty acids, fatty amides, fatty alcohols, emulsifiers (and mineral oil [8012-95-1] in the high soflds paste emulsions), these defoamers required emulsification (brick) or dilution (paste) before use. Liquid defoamers have become the preferred form, insofar as concern about handling and ovemse have been overcome. 

Other carbon electrophiles which are frequently employed include aldehydes, ketones, esters, nitriles and amides of the type RCONMei. An indirect method of acylation involves the initial reaction of a lithio compound with an aldehyde followed by oxidation of the resulting secondary alcohol to the corresponding acyl derivative. 

The conversion of alcohols to esters by O-acylation and of amines to amides by N-acylation are fundamental organic reactions. These reactions are the reverse of the hydrolytic procedures discussed in the preceding sections. Section 3.4 in Part B discusses these reactions from the point of view of synthetic applications and methods. 

A highly selective photochemical chlorination of esters, amides, and alcohols can be effected in 70%-90% H2SO4 using A-chlorodialkylamines as chlorinating agents. Mechanistic studies indicate that a chain reaction is involved ... 

The intermediate formation of covalent inflates is assumed also in the reaction of alcohols with tnflic anhydride in the presence of nitriles to give the corresponding amides [96] (equation 47),... 

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