| 摘要 |
Diisopropylbenzene dihydroperoxides are made by reacting meta- or para-diisopropylbenzene at an elevated temperature, e.g. at 50-150 DEG C., with molecular oxygen to produce a concentrate of monohydroperoxide of at least about 45 per cent by weight, extracting the dihydroperoxide from the oxidized solution by treating with a non-acidic aqueous solution such as dilute sodium hydroxide and subjecting the residual solution to further oxidation. The oxidation may be carried out in the homogeneous phase or in the presence of sufficient water to form a heterogeneous system. The aqueous extract of the dihydroperoxide may be worked up by extraction with benzene or diisopropylbenzene, p by precipitation of the dihydroperoxide from the aqueous extract by adding acid or carbon dioxide, or by evaporating the aqueous extract whereby an alkali salt of the dihydroperoxide is obtained. The extraction may be carried out continuously in a countercurrent manner, or by a batch process. An example is given in which para-diisopropylbenzene is continuously oxidized with an excess of oxygen in the presence of a small amount of a hydroperoxide as initiator. After an initial induction period, the diisopropylbenzene was circulated through an extraction column, the reactor contents being kept slightly alkaline by adding sodium carbonate solution. After about 50 hours the hydroperoxide concentration in the reactor remained steady at about 54 per cent mono- and 4.2 per cent di-hydroperoxide, while the amount of dihydroperoxide extracted per hour had increased to its maximum. Fresh diisopropylbenzene was added continuously to replace the dehydroperoxide removed by the extraction. Using 4 per cent sodium hydroxide solution for the extraction, the extract contained 0.3 to 0.5 parts of monohydroperoxide and 8.5 to 10 parts of dihydroperoxide per 100 of solution. Other examples are given using meta- and para-isomers. |
