Benzotriazole-Mediated Synthesis and Antibacterial Activity of Novel N-Acylcephalexins.

Cephalexin ( 1 ) was acylated using N -acylbenzotriazoles ( 3a - k' ) derived from various carboxylic acids including aromatic, heterocyclic and N -Pg-α-amino acid to afford N -acylcephalexins in excellent yields (82%-96%). Antibacterial screening of the novel cephalosporins revealed that all targets ( 4a - j ) retained the antibacterial activity of cephalexin against Staphylococcus aureus (ATCC 6538). N -Nicotinylcephalexin ( 4c ) and N -(3,4,5-trimethoxybenzoyl)cephalexin ( 4g ) exhibited a broader spectrum of antibacterial activity towards standard strains of Staphylococcus aureus (ATCC 6538), Paenibacillus polymyxa (ATCC 842), and Escherichia coli (ATCC 10536) as well as a resistant strain of Pseudomonas aeruginosa (ATCC 27853).