Preparation of novel 2,3,8-trisubstituted pyrido[3,4-b]pyrazines and pyrido[2,3-b]pyrazines
A four-step synthesis of 8-bromo-2,3-disubstituted pyrido[3,4-b]pyrazines and a six-step synthesis of 8-amino-2,3-disubstituted pyrido[3,4-b]pyrazines have been developed. A particularly valuable feature of this synthetic route is the possibility to build