Abstract:
An efficient and versatile method for the synthesis of imidazopyrazine ring using the modified Pictet-Spengler strategy has been reported. The two step strategy offers rapid assembly of drug-like core templates pyridine or pyrimidine and imidazole into new annulated polycyclic skeletons: pyrido- and pyrimido-imidazopyrazines. The rate of endo cyclization of aryl/heteroaryl- amine substrates have been compared with traditionally used aliphatic amine substrates and results have been discussed in the light of the pKa values of amines present in each substrate.
