Optimización de la síntesis en pasos múltiples de un acilo pirazolidinona

摘要

The modular multistep synthesis of acyl pyrazolidinones such as (9) has been evaluated and optimized. The process begins with unsaturated acids (1) or esters. Reductive amination using aldehydes was used for introducing the N-1 alkyl substituent (3 à 6). A novel N-2-acylation using carboxylic acids can be effected by Mukaiyama’s reagent (6 à 9). NMR (often with solvent suppression) and GC/MS have been used to monitor the progress and purities of reaction. The conditions for rapid chromatographic purification of (6) were evaluated. The modular synthesis was developed for usage in undergraduate organic chemistry laboratory.