Efficient Synthesis of Thieno[2,3-d]Pyrimidines and Related Fused Systems

A convenient synthesis of novel amino acid derivatives with potential antibacterial activity using sustainable materials

Following the principles of green chemistry, cardanol derivatives have been used as renewable, low-cost and easily available natural starting materials to construct a variety of protected and unprotected amino acid derivatives. The reaction of cardanol derivatives with different phthalylamino acids including glycine, alanine, phenylalanine and valine in the presence of N,N′-dicyclohexylcarbodiimide (DCC) as coupling reagent yielded the target compounds in high yields. Deprotection of phthalylamino acid derivatives was achieved by heating with hydrazine hydrate. The chemical structures of all products were confirmed by spectral (FTIR, MS, 1H NMR, 13C NMR) and elemental analyses. The synthesised products were evaluated for their antibacterial activity, and the compounds exhibited potent to weak activity in comparison with a standard drug.