Ethanol → Dimedone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one (dimedone), and R1 -thiolsulfonate, an alkali metal hydroxide, water and a water-miscible solvent, i.e., methanol, ethanol, 2-propanol, acetone, methyl ethyl ketone, dimethylformamide, dioxane or acetonitrile, is heated with stirring at any temperature between about 45°C. and the boiling temperature of the aqueous solvent (preferably at the boiling temperature) for a period of time of about one hour to about 48 hours (preferably three to 24 hours). After the reaction, the solvent mixture is removed by evaporation or by distillation. The residue is washed with water to remove the sulfinate salt by-product, and the crude product is collected on a filter and dried. Purification is accomplished by recrystallizing the crude product from an organic solvent, i.e., a hydrocarbon or lower alkanol such as benzene, cyclohexane, n-hexane, methylcyclohexane, n-pentane, ethanol, aqueous ethanol, methanol, aqueous methanol or toluene or a combination thereof.

Herkunft & Nachweise