Disegno e sintesi di nuovi inibitori di proteine tirosina chinasi a nucleo pirazolopirimidinico

Kinases are enzymes that phosphorylate specific protein and are divided into groups depending upon the residue acting as the substrate for phosphorilation: Serine/Threonine, or Thyrosine. Protein thyrosine kinases are enzymes that transfer the gamma phosphate of ATP to specific thyrosine residues on a wide variety of functional proteins. They play an important role in signal transduction pathways regulating a number of cellular functions, such as growth, differentiation and malignant transformation. The fundamental role that PTKs appear to play in cancer many other diseases has made them attractive therapeutic targets, and has provided the rational for the development of specific inhibitors of these enzymes. EGFR, VEGFR and RET are tyrosine kinase proteins over-expressed in tumour cells (in particular papillary thyroid cancer) and represent a new molecular-target for the treatment of human cancer. The kinase inhibitors are “small molecules” able to act at the intracellular domain, inhibit tyrosine kinase activity. The most important inhibitors are constituted by an anilinoquinazoline structure; moreover in literature compounds with different structures are presented, like heterocycles characterized by a pyrazolopyrimidine core. Thus, my work of thesis have concerned synthesis of new pyrazolo[3,4-d]pyrimidine derivatives with possible inhibitory activity,substituted on N1 with Phenethyl group and on N4 with N-ethyl benzyl amine or Piperazinyl group