Synthesis and Antibacterial Activity of Novel Pyrido[1,2,3-<i>de</i>][1,4]benzoxazine-6-carboxylic Acid Derivatives Carrying the 3-Cyclopropylaminomethyl-4-substituted-1-pyrrolidinyl Group as a C-10 Substituent
Novel pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid derivatives 5-9 carrying a 3-cyclopropylaminomethyl-4-substituted-1-pyrrolidinyl moiety at the C-10 position were synthesized and their in vitro antibacterial activity, intravenous single-dose toxicity, convulsion inductive ability, and phototoxicity were evaluated. It appeared evident that compounds 5a, 6a, 8a, and 9a, which have a cis-oriented 4-methyl or 4-fluoro-3-cyclopropylaminomethyl-1-pyrrolidinyl moiety at the C-10 position, exhibited 2- to 16-fold more potent in vitro antibacterial activity than clinafloxacin against quinolone-resistant Gram-positive clinical isolates. Furthermore, it was obvious that introduction of a fluorine atom to the C-4 position of the 3-cyclopropylaminomethyl-1-pyrrolidinyl moiety reduced intraveneous single-dose acute toxicity and the convulsion inductive ability, and introduction of a fluorine atom to the C-3 methyl group of the pyridobenzoxazine nucleus eliminated the phototoxicity.
Synthesis of (<i>R</i>)- and (<i>S</i>)-Fmoc-Protected Diethylene Glycol Gamma PNA Monomers with High Optical Purity
作者:Wei-Che Hsieh、Ashif Y. Shaikh、J. Dinithi R. Perera、Shivaji A. Thadke、Danith H. Ly
DOI:10.1021/acs.joc.8b02714
日期:2019.2.1
synthetic route has been developed for preparing optically pure, Fmoc-protected diethylene glycol-containing (R)- and (S)-γPNA monomers. The strategy involves the application of 9-(4-bromophenyl)-9-fluorenyl as a temporary, safety-catch protecting group for the suppression of epimerization in the O-alkylation and reductive amination steps. The opticalpurities of the final monomers were determined to be