Amines from acylation

This reaction was first reported by Schotten in 1884 and subsequently extended by Baumann in 1886. It is the acylation of alcohols and amines from acyl halide or anhydride in an aqueous alkaline solution (e.g., 1 M NaOH), and is generally known as the Schotten-Baumann reaction or Schotten-Baumann acylation. Occasionally, it is also referred to as the Schotten-Baumann method,or Schotten-Baumann esterification. Likewise, the formation of benzoyl ester under these conditions is called the Schotten-Baumann benzoylation." It is assumed that the reaction would perform well if carried out in a biphasic system of water and an immiscible organic solvent (e.g., CH2CI2), which has an important application in the acylation of amino acids.For example, p-nitrohippuric acid and dibenzoylornithine (ornithuric acid) all can be prepared under these conditions. 

Amines from acyl hydroxamates CONHOAc CH2NH2... 

From the outset, the further O acylation of the initial ketonic products was recognized. Detailed studies have been made of the benzoylation of morpholinoeyclohexene (379-382) and of the effect of the amine moiety of cyclohexanone derived enamines on the ratio of produets (iS5) obtained from acylations. 

Acyl azide, amines from, 935 Acyl carrier protein, function of, 1 140 Acyl cation, electrostatic potential map of, 558... 

Figure 1.8 Derivatives of amines can be prepared from acylating or alkylating agents to give amide, secondary amine, or tertiary amine bonds.

Further investigation on the chemistry of the very potent diuretic drug ethacrinic acid W led to a compound that retained the high potency of the parent with reduced propensity for causing side effects, such as loss of body potassium and retention of uric acid. Friedel-Crafts acylation of dichioroanisole with phenyl acetyl chloride gives ketone 10. This is then reacted in a variant of the Mannich reaction which involves the aminal from dimethyl-... 

The synthesis of amines from oximes is exemplified by the reduction of oxime 332 to 333 (99W032453) and of bicyclic oximes (derived from ketones 3 and 23a), for instance, of oxime 387 (Scheme 87) to amine 388 that is acylated to yield potential pharmaceutical agent 390 (92BML1147). Nucleophilic substitution of chloropyridine 384 generates morpholino derivative 385 (76IJB400). 

Acylation of A-hydroxy-2-phenylbutyramidine (112-1) with 3-chloropropionyl chloride in the absence of an added base proceeds as might be expected to give the product (112-2) from acylation on the more basic nitrogen. Heating this compound leads to the formation of the oxadiazole (112-3) almost certainly via the enol tautomer of the amide. Displacement of the terminal chlorine with diethylamine leads to the tertiary amine and thus proxazole (112-4) [123], a compound that is said to exhibit antispasmodic activity. 

Chiral amines are valuable synthons that dominate agrochemicals and pharmaceutical drug pipelines. Current methods for the preparation of amines are largely based upon resolution, and this is an excellent example of an industrial success. BASF makes a range of chiral amines by acylating racemic amines with proprietary esters, whereby one enantiomer is acylated to the amide, which can be easily separated from the unreacted amine [7]. For example, the resolution of racemic 15 in... 

Nu = alcohol, amine Scheme 5.13 Preparation of P-keto esters and amides from acyl Meldrum s acids... 

Amines are important synthetic intermediates, and numerous protective groups have been developed for temporarily preventing amines from being acylated or alkylated. The following sections cover protective groups for amines that can be introduced or removed on insoluble supports. The development of such protective groups was mainly driven by solid-phase peptide synthesis. A more detailed collection of protective groups can be found in [230],... 

Amides can be obtained from acyl halides, carboxylic anhydrides, or esters with amines or ammonia. The mechanisms of these reactions are very similar to the corresponding reactions of alcohols ... 

From acyl chlorides and ammonia or amines Most amides are prepared by this... 

Amines also add to the carbonyl carbon of aldehydes and ketones, but the reactions take a different course from acylation and, with ammonia or a primary... 

In the presence of a base, acid chlorides react readily with aziridines to give acylated aziridines (2,22,160—163). In the absence of a base, however, ring opening takes place and 2-chloroethylamides are obtained (2,164). Under suitable conditions acylated trialkylammonium salts of ethylenediamine can be prepared from acid chlorides, ethyleneimine, and tertiary amines (71). Acylated aziridines can be rearranged to 2-oxazolines by the action of heat, nucleophiles, or acids. The rearrangement of thioacylaziridines proceeds analogously (7,8,165—171). 

Compound A is an ester but has within it an amine function. Acyl transfer from oxygen to nitrogen converts the ester to a more stable amide. 

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