Efficient Synthesis and Deprotection of Semicarbazones under Solvent-Free Conditions

Abstract

<em>Effective methodologies for efficient preparation of semicarbazones from aldehydes or ketones via milling and the subsequent regeneration of the parent carbonyls by gaseous nitrogen dioxide are described under solid-solid and gas-solid reaction conditions, respectively. These methods are fast, simple and environmentally benign which do not require the use of any auxiliaries such as catalysts or solid supports in their procedures.</em>