2‐Amino‐4‐arylthiophene‐3‐carbonitrile and formamidine acetate as key building units for the synthesis of 5‐arylthieno[2,3‐d]pyrimidin‐4‐amines

Abstract

We tried to establish a method for the synthesis of 5‐arylthieno[2,3‐d]pyrimidin‐4‐amine analogues via three‐step reactions and examined the changes in the solvent, time, and temperature. A novel condition has been developed for the preparation of substituted 2‐aminothiophenes employing the Knoevenagel condensation followed by the Gewald method and in the last step to form thieno[2,3‐d]pyrimidines by using formamidine acetate. All the synthesized 5‐arylthieno[2,3‐d]pyrimidin‐4‐amines are unknown and were characterized by IR, ¹H‐NMR, ¹³C‐NMR, and CHN analysis.