Dimethyl Sulfate → HCID 54039577, compound

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Reaction Steps

6.13 g of a 55-60% sodium hydride dispersion in 100 ml of benzene are placed in a reaction vessel equipped with stirrer, thermometer, reflux condenser and dropping funnel and a solution of 20.0 g of 2,6-dimethyl-6-nonen-5-ol in 100 ml of benzene is added dropwise thereto over a period of 30 minutes while stirring at room temperature. In order to complete the reaction, the mixture is held at reflux temperature for 12 hours. The mixture is subsequently cooled to 20° C. At this temperature there are gradually added dropwise 20.7 g of dimethyl sulphate so that the temperature does not exceed 35° C. (exothermic reaction). After completion of the addition, the mixture, which becomes thicker, is heated to reflux temperature for a further 4 hours, then cooled and treated with 25 ml of methanol. After 5 minutes, there is added dropwise a solution of 6.7 g of sodium hydroxide in 40 ml of water and the mixture is again heated to reflux temperature. After cooling, the product is taken up in ether, washed neutral with water and the solvent is distilled off over a Vigreux column. The crude product remaining behind is rectified under a water-jet vacuum with the addition of 0.1 g of sodium carbonate and yields 13.3 g (61.7% of theory) of pure 5-methoxy-2,6-dimethyl-6-nonene of boiling point 78° C./12 Torr, nD20 =1.4339. Odour: sweet, fruity, powdery, green.

Provenance & Evidence