European journal of organic chemistry issue:18 pages:4257-4269
The synthesis of a pyrido[4,3-d]pyrimidine library from 4,6-diamino-2-bromonicotinamide and 4,6-diaminonicotinamide is described. A systematic variation of the substituents at positions 2, 4, 5 and 7 of the pyrido[4,3-d]pyrimidine scaffold was carried out, leading to a wide variety of structural analogues. This strategy led to the discovery of a new structural class of PDE-4 inhibitors. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.