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Further, T3P has also been employed to activate the hydroxamtes leading to isocyanates via Lossen rearrangement 34. NHC–catalyzed Synthesis of Hydroxamic Acids N-Heterocyclic carbene NHC catalyzed amidation of a variety of aryl, alkyl, alkenyl and heterocyclic aldehydes with nitroso compounds is a powerful method for the synthesis of N-aryl hydroxamic acids in excellent yields. Chemoselective Esterificaiton Using Imidazole Carbamates Imidazole carbamates and ureas are used as chemoselective esterification and amidation reagents. A simple synthetic procedure allows the conversion of a wide variety of carboxylic acid to hydroxamates. Synthesis of Weinreb Amides Using Triazime Intermediates De Luca et al 37 reported the successful large scale synthesis of weinreb amide through a convenient and simple one-flask method via 2-chloro-4,6-dimethoxy-1,3,5-triazine intermediate 20. To achieve this, the ester 0.5 M in methanol and hydroxyl amine 10 eq was reacted in the presence of sodium methoxide 1 eq. Following an optimization studies, they found that at 70 and 30 min, highest yield of the hydroxamate was obtained with high purity. Microware Activated Hydroxamic Acid Synthesis Massaro et al 33 has shown that the reaction of esters with hydroxylamine in the presence of a base under microwave activation provides hydroxamic acids in good yield and high purity. 17, 18 These class of compounds are used in the design of therapeutics targeting cancer 19, 20 e.g. histone deacetylases HDACs inhibitors like vorinostat, belinostat, panobinostat and trichostatin A, 21 cardiovascular diseases 22 e.g. hydroxyurea, 24 Alzheimer s, 25 malaria 26, 27 e.g. Keywords: Keyword Histone deacetylase inhibitors, Matrix metalloproteinase inhibitors, HIV, Hydroxamaates, Ribonucleoside diphosphate reductase Cite this paper: David I. The reasonable way of producing hydroxamic acid derivative is the reaction of hydroxylamine with acid chlorides or esters. 13 Hydroxamic acids are capable of inhibiting a variety of enzymes, including ureases, 14, 15 peroxidises 16, and matrix metalloproteinases.
From the perspective of small molecule activation, carbodiimides are. Hydroxamates such as fosmidomycin and desferrioxamine B are potent antimalarial agent. Ugwuja, Synthesis and Biological Applications of Hydroxamates, American Journal of Organic Chemistry, Vol. 3 Their mode of action results from the formation of bidentate ligand with active site of zinc. The TBS group was later recovered with tetra- normal-butylammonium fluoride TBAF in THF to give alcohol 28 in 91 yields. The second portion of the synthesis is presented in schemes 10. The syntheses of various classes of hydroxamates and their mode of biological applications have been reviewed. 4 Much of their activities are due to their chelating properties with metal ions, especially with transition metals, hence constituting a very important class of chelating agents with versatile biological activities. The broad biological activities of hydroxamates and the need to improve on their synthetic routes informed the review of their synthesis and biological applications. 5, 6 A number of synthetic routes are available for the preparation of hydroxamic acids, 7-12 but some are tedious, time consuming and costly as well. Colombo, An improved synthesis of the HDAC inhibitorn trichostatin A, Master s Theses and Doctoral Dissertations, Eastern Michigan University, 2009, 1-2.