Synthesis of novel phenylalaninol-based benzamidesas dopamine receptor ligands

The formation of amides has attracted considerable interest due to their importance in organic and bioorganic chemistry, their value as intermediates in organic synthesis and a wide range of applications in the chemical industry. The amide bond is an important structural component of peptides, polymers and many natural products and pharmaceuticals.Numerous amides are biologically active and show antifungal, antihistamine, anthelmintic, and antibacterial properties.[1] Amides show biological activity in a variety of ways when they are conjugated to aliphatic, aromatic rings, and heterocyclic rings [2]. In First, we began this study by preparing L-phenylalaninol in one step from the reduction of corresponding amino acid namely L-phenylalanine1under standard conditions using NaBH4-I2 in dry THF [3].The conversions of phenylalaninolinto the corresponding N-alkyl, allyl or propargyl amino alcohol derivatives were carried out through its reaction with N-tert-butyloxycarbonyl-2-bromo-laminoethane and Intermediate 2was synthesized by Boc-deprotection with HCl gas in ethyl ether. Finally compound 2 coupled with 2,6- dimethoxy benzoyl chloride for synthesis of new phenylalaninol-based benzamides. All characterization data including IR,1H and 13C NMR of products were in agreement with the proposed structures.