A new technique for synthesis of 2,4-dichloro-thieno[3,2-d]pyrimidine

3-Amino-2-methoxycarbonylthiophene used as the main raw material, an intermediate (thiofuran siamese) 2,4-dichloro-thieno[3,2-d]pyrimidine was synthesized. The product was characterized by nuclear magnetic resonance (NMR). The first step yield was 84% (190 °C) and the second step yield was 81.4% (105 °C, m (intermediate):m (phosphorus oxychloride) = 1:6.4). The raw product was refined with a unique refining process, which can enhance the purity up to 99.5% to meet the requirement of conditions for the development and research of thiofuran siamese as a new medicine of anticarcinogen. Contrasted with the traditional technique, this process featured with cheap raw materials, possible for solvent recovery and reuse, low comprehensive cost, and suitable for production on certain scale.