Prepartion of Benzyl benzoate

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Prepartion of Benzyl benzoate  Empty Prepartion of Benzyl benzoate

Post  yufei on Thu Jul 28, 2011 9:10 am

Benzyl benzoate Benzyl benzoate , its cas register number is 120-51-4. It also can be called Benylate ; Benzoic acid, benzyl ester ; Benzoic acid, phenylmethyl ester ; Phenylmethyl benzoate ; Novoscabin ; Peruscabin ; Peruscabina ; Scabagen ; Scabanca ; Scabide ; Scabiozon ; Scabitox ; Scobenol ; Spasmodin .It is a colourless oily liquid with pleasant aromatic odor.
Benzyl benzoate (CAS NO.: 120-51-4),could be produced through the following synthetic methods.

Three grams (0.13 atom) of metallic sodium is dissolved by warming for one-half hour in 70 g. (0.65 mole) of pure benzyl alcohol, and after the mixture has cooled to room temperature the solution is added gradually, with thorough mixing, to 454 g. (4.3 moles) of c.p. benzaldehyde (which must contain less than 1 per cent of benzoic acid). The reaction mixture has a tendency to become warm, but the temperature should be kept slightly below 50–60° by cooling, if necessary. A pasty gelatinous mass results. After about one-half hour the temperature of the mixture no longer rises; it is then warmed on the water bath for about one or two hours, with occasional shaking.

The cooled reaction product is treated with 200 cc. of water, the layer of oil separated, washed once with a second portion of water, and subjected to distillation under reduced pressure. The first fraction of the distillate contains benzyl alcohol together with unchanged aldehyde, as well as a small quantity of water. The temperature then rises rapidly to the boiling point of benzyl benzoate, when the receiver is changed. The product boils at 184–185° /15 mm., and analysis by saponification shows it to consist of 99 per cent ester. The yield is 410–420 g. (90–93 per cent of the theoretical amount). This benzyl benzoate supercools readily, but after solidifying melts within one degree of the highest recorded value (19.4°) and therefore need not be refractionated, unless material of exceptional purity is required.


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