Polymer-Supported Synthesis of Hydroxamic Acids

Significance

Polymer-bound N-hydroxyben­zenesulfonamide (2) was prepared by treatment of polystyrene sulfonyl chloride (1) with pyridine solution of HCl·NH₂OH in CH₂Cl₂. The reactions of resin 2 with several aliphatic and aromatic aldehydes in the presence of NaOMe in THF gave the corresponding hydroxamic acids 3. The desired hydroxamic acids 3 were isolated in 40-99% yields and 97-99% purities after treatment of the crude mixtures with the acid-ion-exchange resin and polystyrene sulfonylhydrazide to remove the excess NaOMe and unreacted aldehydes.