| 摘要 |
1,3-Dithiol-2-ylidene derivs. of formula (I) are new. (R and R1 are each lower alkyl, cycloalkyl, lower alkoxyalkyl, (substd.) aryl, (substd.) aralkyl or (substd.) heterocycle). - Prodn. of (I) comprises reacting a beta-diketone (II) with a dithiolium salt (III) in the presence of base. (R2 is lower alkyl or aralkyl; and X is an anion residue). Reaction is effected in inert solvent in the presence of base at 0 deg.C to below reflux. Solvent is chosen from tetrahydrofuran, dioxan, methanol, acetic acid, DMSO and DMF. Examples of the base are metallic sodium, sodium hydride, sodium methoxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, pyridine, triethylamine and dimethylaniline.
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