Synthesis of sodium alkoxides

WillD

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About 100 ml of alcohol (methanol, ethanol, n-propanol) was taken in the reaction vessel and stirred continuously using a magnetic stirrer. Argon gas, purified by passing through a column of silica–gel to remove traces of moisture, was let into the reaction vessel to provide inert gas cover while carrying out sodium–alcohol reaction as well as to dilute the hydrogen gas produced during the reaction. Solid sodium pieces weighting 500–1000 mg were added to the alcohol. The reaction was initially carried out at room temperature and then the temperature was gradually raised to near boiling point of the respective alcohol to dissolve as much sodium as possible and the addition of sodium was stopped when the solution was saturated. Stirring and heating were stopped and the saturated sodium alkoxide solution was allowed to cool naturally for about 16 h to facilitate formation of sodium alkoxide crystals and completion of crystallization process. The excess alcohol was then removed by vacuum distillation and the evolved alcohol was trapped by condensing the vapour in a thermostat trap maintained at 183 K using liquid nitrogen–acetone slurry. The crystalline sodium alkoxide was dried under a dynamic vacuum of 10–2 mbar for 16 h at room temperature and then at high vacuum of 10–5 mbar for 8 h. The drying process was carried out initially at 303 K for 8 h and the remaining period at 323 K. Dry milky white fine crystals of sodium alkoxides were transferred into a leak tight glass container and preserved in a high purity argon atmosphere glove box. A typical photograph showing crystalline sodium n-propoxide:
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