Electrophilic Amination of 4-Fluorophenol with Diazenes: A Complete Removal of the Fluorine Atom
摘要:
The electrophilic amination of 2-fluorophenol, 4-fluorophenol, and 2-chlorophenol was observed to occur as a result of their treatment with diazenes 1-4 under mild reaction conditions in the presence of ZrCl4. The products originating from the 2-fluorophenol or 2-chlorophenol can be considered as "normal" products of amination. On the other hand, the 2-chloro-4-amino-substituted phenols obtained from the 4-fluorophenol seem to be formed in a process that involves an ipso amination, the complete removal of the fluorine atom, and the introduction of the chlorine atom.
Diazenedicarboxamides as inhibitors of d-alanine-d-alanine ligase (Ddl)
摘要:
D-Alanine-D-alanine ligase (Ddl) catalyzes the biosynthesis of an essential bacterial peptidoglycan precursor D-alanyl-D-alanine and it represents an important target for development of new antibacterial drugs. A series of semicarbazides, aminocarbonyldiazenecarboxylates, diazenedicarboxamides, and hydrazinedicarboxamides was synthesized and screened for inhibition of DdlB from Escherichia coli. Compounds with good inhibitory activity were identified, enabling us to deduce initial structure-activity relationships. Thirteen diazenedicarboxamides were better inhibitors than D-cycloserine and some of them also possess antibacterial activity, which makes them a promising starting point for further development. (c) 2007 Elsevier Ltd. All rights reserved.