Methyl Ethyl Ketone → HCID 86743108, compound

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Reaction Steps

With stirring, 424.5 g (2.0 moles) of benzoin are added to 650 ml of methyl ethyl ketone in a 2.5 liter sulfonating flask. The resultant beige suspension is stirred for 5 minutes, then 400.4 g (2.1 moles) of pulverised p-toluenesulfonyl chloride are added. No chemical reaction takes place as yet. The temperature falls from room temperature to c. +5° C. When the addition is complete, the suspension is stirred for a further 5 minutes and then 50 ml of deionised water are added. Then 293.3 g of 30% aqueous sodium hydroxide solution (corresponding to 2.2 moles of NaOH) are added dropwise over 30 minutes, while keeping the temperature at 10°-15° C. by cooling with an ice bath. The beige suspension is efficiently stirred at this temperature for 6 hours, then cooled to -10° to -15° C. and vigorously further stirred for a further hour at this temperature. The beige crystal slurry, which is readily stirrable up to the end, is isolated by filtration, washed with 1 to 3×200 ml of deionised water and thereafter once with 150 ml of aqueous ice-cold methyl ethyl ketone, and dried under vacuum at room temperature, to give 674 g (92% of theory) of benzoin p-toluenesulfonate in the form of white crystals which melt at 99°-101° C. The purity of the product is at least 98% according to analysis by thin-layer chromatography and NMR spectroscopy. A sample stirred in water shows no acid reaction to litmus paper.

Provenance & Evidence