Development of the One-Carbon Homologation of a 4-Methylcoumarin Assisted by In-Line FTIR

In-line FTIR was applied as a suitable PAT (process analytical technology) to monitor and control the enolate formation step in the one-carbon homologation process of a 4-methylcoumarin with chloromethyl pivalate. The techniques to determine the endpoint of the reaction and to obtain kinetic and stability data both in THF and DMF as reaction solvent are presented. The valuable chemical data obtained by this PAT was used to support the scale-up of the homologation process.