The Vilsmeier reagent as an efficient acid activator for the synthesis of β-lactams

Synthesis, in vitro biological evaluation and in silico molecular docking studies of novel β-lactam-anthraquinone hybrids

Schiff bases from 2-aminoanthraquinone have been prepared by reaction with aldehydes and used to prepare novel β-lactam-anthraquinone hybrids via [2+2] ketene-imine cycloaddition (Staudinger reaction) reaction. In vitro antibacterial studies of all synthesized compound were carried out against three gram-positive strains Staphylococcus aureus (Methicillin-resistant strain), Enterococcus faecium (Vancomycin-resistant strain) and Bacillus subtilis, and two gram-negative strains Escherichia coli and Pseudomonas aeruginosa. These compounds were further evaluated for their in vitro antifungal activity against Candida albicans, Aspergillus niger and Trichophyton mentagrophytes. Hybrid compounds showed moderate to excellent antibacterial and antifungal activities. Surprisingly, among the tested compounds, some of them revealed equal antibacterial and antifungal properties and even better than standards. In addition, results demonstrated that the new hybrids are very promising antibacterial agents against resistant strains. Also molecular docking studies were carried out by Autodoc software. Penicillin-binding protein 2a (PDB ID: 1VQQ) from methicillin-resistant Staphylococcus aureus strain used as a target which good binding interactions were observed.

Silphos as an efficient heterogeneous reagent for the synthesis of 2-azetidinones

This report provides a description of an efficient and simple procedure for the synthesis of 2-azetidinones

One-step Synthesis of β-lactams Using Cyanuric Fluoride

Cyanuric fluoride works as an efficient acid activator reagent for the direct [2+2] ketene–imine cycloaddition of substituted acetic acids and imines in a one-pot synthesis under mild conditions. The yields are good to excellent and the reaction conditions are mild, simple and efficient.

Design and synthesis of 2-aminothiazole based antimicrobials targeting MRSA

Privileged structure-based libraries have been shown to provide high affinity lead compounds for a variety of important biological targets. The present study describes the synthesis and screening of a 2-aminothiazole based compound library to determine their utility as antimicrobials, focusing on MRSA. Several of the compounds in this series demonstrated improved antimicrobial activity as compared to ceftriaxone (CTX), a β-lactam antibiotic. The most potent compound (21) had MICs in the range of 2-4 μg/ml across a panel of Staphylococcus aureus strains. In addition, trifluoromethoxy substituted aminothiazoles and aminobenzothiazoles were found to be potent antimicrobials with MICs of 2-16 μg/ml.

One-Pot Sequence Synthesis of Azetidin-2-One Using Diethyl Chlorophosphate

A simple and convenient synthesis of 2-azetidinone derivatives from the reaction of a pre-mixture of amines and aldehydes with carboxylic acids in the presence of diethyl chlorophosphate by [2+2] cycloaddition reaction is described. Separation and purification of imines as intermediates were not required. The methodology is convenient and good to excellent yields of products were obtained with simple purification.

Synthesis of some new mono- and bis-polycyclic aromatic spiro and bis-nonspiro-beta-lactams

Some new mono-and bis-polycyclic aromatic spiro-beta-lactams and bis-non spiro-polycyclic aromatic beta-lactams have been synthesized from imines derived from anthracene-9-carbaldehyde, 2-naphtaldehyde and a ketene derived from 9H-xanthene-9-carboxylic acid and phenoxyacetic acid by a [2+2] cycloaddition reaction. The cycloadducts were characterized by spectral data, including 1H-NMR, 13C-NMR, IR and elemental analyses. The configurations of some of these mono-spiro-beta-lactams were established by X-ray crystal analysis.