Synthesis of N-methylthieno [2, 3-d] Pyrimidin-4-amine Thienopyrimidine

Thieno[2, 3-d]pyrimidine is a key intermediate in many biologically active compounds such as GDC-0941 and BKM 120. In this work, a rapid synthetic method for compound (4) was established. The compound (4) was synthesized from the commercially available methyl 2-aminothiophene-3-carboxylate and formimidamide through three steps including condensation reaction, chlorination, and nucleophilic substitution. The structure was confirmed by MS and H-1 NMR. Furthermore, the total yield of the three steps was 54%.