Synthesis of Quinoxaline Macrocycles

The formulas of macrocycles-predecessors of quinoxaline macrocycles-are presented below (Fig. 5.1). 

The earlier members of this series (n = 2-6) had been prepared by Stetter (1953) when A,A-ditosyl-l,2-DAB is affected by a, -dibromoalkane, followed by the hydrolysis of the ditosyl derivative 9. 

---

Commercially available 2,3-dibromomethylquinoxaline 61a was widely used for the synthesis of quinoxaline macrocycles. Its interaction with l,l-bis(imidazolyl)methane 91a, 2,6-bis(imidazolylmethyl)pyridine 91b, 2,3-bis(imidazolylmethyl)quinoxaline 91c, and l,l -bis(imidazolylmethyl) ferrocene 91d leads to the quinoxaline macrocycles 92a—d, respectively, which are fluorescent receptors on anions (2008JCS(D)3694,20070L485, 2010CSR1457). 

There are a number of methods for the synthesis of quinoxaline macrocycles that have been successfitlly implemented for constructing quinoxalinoporphyrins, quinoxalinoporphyrazines, quinoxalinocrown ethers, quinoxalinocavitands, quinoxalinohemispherands, and hybrid ... 

Commercially available 2,3-dibromomethylquinoxaline 72a was widely used for the synthesis of quinoxaline macrocycles. Its interaction with the 1,1-bis... 

There are a number of methods for the synthesis of quinoxaline macrocycles that have been successfully implemented for constructing quinoxahnoporphyrins, quinoxalinoporphyrazines, quinoxalinocrown ethers, quinoxalinocavitands, quinoxalinohemispherands, and hybrid macrocycles. In these macrocyclic systems, quinoxaline moiety(ies) were attached to the macrocyclic skeleton by the atoms N(l) and C(3), N(l) and N(4), C(2) and C(3), C(2) and C(8), C(6) and C(7). In these cases, macrocyclic systems in which the quinoxaline moiety is fixed in a macrocyclic skeleton by atoms of C(2) and C(3) are represented best of all. Considerably less attention is paid to their 6, 7 analogs, and all the others are represented in single works. 

---