Phase-transfer catalyzed condensation of 3-methyl-5-pyrazolone with carbon disulfide and alkyl bromides

Article abstract of DOI:10.1055/s-1991-26500

Reaction of 3-methyl-5-pyrazolones with carbon disulfide and alkyl bromides under phase-transfer catalysis to give alkyl 5-hydroxy-3-methyl-1H-pyrazole-4-carbodithioates is described. Using 1,2-dibromoethane or 1,3-dibromopropane, the corresponding cyclic