Synthesis, Characterization, Antimicrobial Activity of Novel N-Substituted β-Hydroxy Amines and βHydroxy Ethers Contained Chiral Benzoxazine Fluoroquinolones

Abstract

Synthesis of novel N-substituted β-hydroxy amines 4(a-j) and β-hydroxyethers 5(a-c) with chiral benzoxazine fluoroquinolones has been described. Benzoxazinefluoroquinolone carboxylic acid 1, on reaction with piperizine in acetonitrile in presence of triethylamine under reflux gives 7- piperazinyl benzoxazine fluoroquinolone 2. The latter is reacted with epichlrohydrine in presence of NaOH in acetone to yield respective N-substituted epoxide 3 with retained chirality, the 3 on treatment with different amines gives respective β-hydroxy amines 4(a-j). On other hand, 3 on treatment with alcohols in presence of NaOH afforded the corresponding β-hydroxy ethers 5(a-c). The structures of the synthesized compounds have been established on the basis of its spectral and analytical data. The antimicrobial activity of newly synthesized compounds ware evaluated against different microorganisms comparing with levofloxacin and found all the compounds exhibited remarkable activity. Keywords: Antimicrobial activity, Chiral benzoxazine fluoroquinolones, Epichlorohydrine, 7-Piperazinyl chiral benzoxazine fluoroquinolones, spectrum antibiotics, FDA, piperazinyl fluoroquinolones, pharmacophore, Gram-positive, piperazine ring