Alkyl-bis(5-hydroxy-3-methyl-1-phenyl-1H-pyrazole-4-carbodithioates) are interesting targets as they are useful complexing agents for transition metal ion extraction. Anyhow, the intents of their synthesis lead to heterocyclic products and not to the desired molecules. To gain insight into the reaction, we carried out a theoretical investigation on the reaction mechanism and the involved activation energies and the relative thermodynamic stabilities of the desired and obtained. © 2022 Informa UK Limited, trading as Taylor & Francis Group.