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 ketene dithioacetals are formed.
Organic soluble metal-azo and metal-azomethine dyes
申请人:Minnesota Mining and Manufacturing Company
公开号:US05461155A1
公开(公告)日:1995-10-24
Metal-Azomethine dyes with excellent solubility in organic media. The dyes have an arene nucleus and are substituted, in part, with a non-free-radically polymerizable alkyldiketonate or 8-hydroxyquinolate ligand. The dyes are useful in dye diffusion transfer processes.