Diacylamine formation

If instead of the acetyl group, a residue with a functional group (OH, NH2, SH) participates in diacylamine formation then interesting insertion and rearrangement reactions can be observed as described in a forthcoming section (p. 195). 

Hagenmaier and Frank (1972) have reported the possibility of diacylamine formation using DCC and a large excess of carboxyl component that ultimately may result in either chain shortening or chain lengthening. However, very few cases of this have been reported (Mitchell and Roeske, 1970). 

Similar reactions involving polymer amide anions yield the corresponding diacylamine structures along with substituted /3-oxoamides, keto amides (XIII) and (XIV). In this way, the sequence of condensation and transacylation results in the formation of five types of 3-keto acid derivatives (X)—(XIV). 

Amine hydrochlorides are known to react at elevated temperature with diacylamines and amides with the formation of amidines [201]... 

Reaction of nitrones with aroyl chlorides in the presence of triethylamine yields lV,lV-diacylamines (equation 58). The reaction can be rationalized by formation of an aroyloxy(benzylidene)ammonium chloride, with elimination of the carboxylic acid and readdition of carboxylate to the nitrilium ion followed by 1,3-acyl shift to give the /VjV-diacylamine. 

Einhorn-Brunner reaction. Formation of substituted 1,2,4-triazoles by condensation of hydrazines or semicarbazides with diacylamines in the presence of acid catalysts. 

Furthermore, polymer amide and imide (diacylamines) groups may undergo reaction with terminal NH2 as well, according to the same reaction pathways depicted in Schemes 8 and 9, respectively. The result is the formation of amidine and acylamidine structures (24 and 25) inside the polymer chain, representing points of branching ... 

---