G. L. Kamalov

Kinetics and mechanism of bromination of cyclic acetals with 1,4-dioxane dibromide

It is shown that the reactivities of cyclic formals in the case of bromination with dioxane dibromide increase in the order 1,3-dioxepane > 1,3-dioxalane ≫ 1,3-dioxane, which is explained not only by steric factors but also by the ease of cleavage of the C4-O3 bond of the dioxacyclane ring. The bromination of cyclic acetals takes place through prior enolization of the cyclic acetal with subsequent electrophilic addition of bromine to the double bond.

Interaction of N,N′-polyoxyethylenediphthalimides with diethylenetriamine and mass spectral behavior of the macrocyclic diamides of phthalic acid formed

The reaction of diethylenetriamine and diphthalimides containing a polyoxyethylene fragment yielded macrocyclic diamides of phthalic acid, and the fragmentation of these compounds under the action of electron impact was studied. It was established that their decomposition consists of an initial ejection of a C2H4N radical, presuming a rearrangement of the molecular ions to the corresponding N-substituted phthalimides, followed by the splitting out of ethylene oxide and water molecules in various orders. These mass spectral principles can be used to establish the number and sequence of monomer units in the macrocycles.

Peculiarities of the reaction of N,N′-substituted diphthalimides with amines

Macrocyclic phthalic acid diamides were obtained by the reaction of N,N′-substituted diphthalimides with polyoxyethylenediamines, while the corresponding tetraamides were obtained with primary aliphatic amines. It is shown that the reaction is a thermodynamically controlled process.

Character of the products of bromination of 1,3-dioxacyclanes with N-bromosuccinimide

The dependence of the character and composition of the products of the reaction of equimolar amounts of N-bromosuccinimide and 1,3-dioxacyclanes on the ring size and the character of the substituent in the 2 position of the 1,3-dioxacyclane ring was examined. Reasons for the primary formation of bromination products of different types for five-, six-, and seven-membered cyclic acetals are proposed.