Organic Syntheses, Coll. Vol. 1, p.494 (1941); Vol. 8, p.102 (1928).
Caution! Reactions and subsequent operations involving peracids and peroxy compounds should be run behind a safety shield. For relatively fast reactions, the rate of addition of the peroxy compound should be slow enough so that it reacts rapidly and no significant unreacted excess is allowed to build up. The reaction mixture should be stirred efficiently while the peroxy compound is being added, and cooling should generally be provided since many reactions of peroxy compounds are exothermic. New or unfamiliar reactions, particularly those run at elevated temperatures, should be run first on a small scale. Reaction products should never be recovered from the final reaction mixture by distillation until all residual active oxygen compounds (including unreacted peroxy compounds) have been destroyed. Decomposition of active oxygen compounds may be accomplished by the procedure described in Korach, M.; Nielsen, D. R.; Rideout, W. H. Org. Synth. 1962, 42, 50 (Org. Synth. 1973, Coll. Vol. 5, 414). [Note added January 2011].
To a solution of 42 g. (0.30 mole) of perbenzoic acid (p. 431)
in 500 cc. of chloroform
is added 30 g. (0.29 mole) of styrene
) (p. 440)
. The solution is kept at 0° for twenty-four hours and is shaken frequently during the first hour. At the end of twenty-four hours, titration of an aliquot part of the solution shows that only the slight excess of perbenzoic acid
remains (Note 1)
The benzoic acid
is removed from the chloroform
solution by shaking with an excess of 10 per cent sodium hydroxide
solution, the alkali is removed by washing with water, and the chloroform
solution is dried with anhydrous sodium sulfate
. It is then fractionated through an efficient distilling column (p. 130)
. Removal of the chloroform
leaves a practically colorless liquid which distils at 188–192°
(uncorr.) (Note 2)
. The yield is 24–26 g.
per cent of the theoretical amount).
If the styrene oxide
is distilled over a free flame some decomposition takes place as indicated by the formation of water. This is not observed if the product is distilled from an oil bath
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