Facile synthesis of alkynyl-, aryl- and ferrocenyl-substituted pyrazoles via Sonogashira and Suzuki-Miyaura approaches

Synthesis of Thiophene/Furan-Artemisinin Hybrid Molecules

Natural products with semi-synthetic molecules displays higher biological activities, and creates new biological properties for the treatment of diseases. Although, natural products like artemisinin have been used as a traditional medicine over thousands of years, structure and biological properties of many natural products were investigated in the 20th century.  Design and synthesis of new biologically active compounds including natural products have very critical roles to find novel drug candidates. Herein, novel thiophene/furan bridge artemisinin derivatives were synthesized by starting from artemisinin.  Firstly, benzothiophene derivatives are synthesized, then Stergich esterification reactions give the new artemisinin hybrid molecules with moderate to high yields.

Synthesis of novel artesunate-benzothiophene and artemisinin-benzothiophene derivatives

Natural products are used for the treatment of a variety of diseases for many years. Last decades, design and synthesis of novel biologically active hybrid molecules including natural product is gained big importance due to their unique and new biological properties. In the present study, novel artemisinin-benzothiophene derivatives (12 A-F) are synthesised. Initially, benzothiophene derivatives (4 A-4F) are prepared via the Pd-catalyzed coupling reactions and iodocyclisation reactions. Then, Suzuki-Miyaura coupling reactions were used for the formation of intermediates 6 A-6F (between 64% and 91% yields). Finally, the Steglich esterification reaction between intermediate 6 and artesunate formed the artemisinin-benzothiophene hybrids (9 A-9F) in moderate to excellent yields under very mild reaction conditions. When intermediate 6 was reacted with dihydroartemisinin, product 12 A-12F was also obtained with high yields.