Patent GB-786340-A (GB)
Title: Extraction of organic hydroperoxides
Inventor: BENTON JAMES LIPP BROWN
IPC: C07C407/00
Filed: 1954-08-18
Abstract: Hydroperoxides are recovered from the products of oxidation of the corresponding hydrocarbons by contacting the oxidate with a homogeneous mixture of a lower alkanol and aqueous alkali metal hydroxide solution, where by the hydroperoxides are extracted into the aqueous alcoholic alkali solution.  The term "lower alkanol" means an alkanol having from one to four carbon atoms which is miscible with the aqueous alkali, e.g. methanol, ethanol, isopropanol or t-butanol.  Examples of hydroperoxides which may be recovered are: n-decane monohydroperoxide, 2-methylundecane monohydroperoxide, m- and p-diisopropylbenzene monohydroperoxides, 3 - phenylpentanmonohydroperoxide, 1 - ethyl - 1 : 2 : 3 : 4 - tetrahydronaphthalene - 1 - hydroperoxide, 1 : 4-dimethyl - 1 : 2 : 3 : 4 - tetrahydronaphthalene-1-hydroperoxide, 1 : 4 - diethyl - 1 : 2 : 3 : 4-tetrahydronaphthalene - 1 - hydroperoxide and 1-methyl - 3 - phenylindane monohydroperoxides.  The process may be effected by single or multi-stage batch extractions or by continuous countercurrent extraction.  The extraction mixture preferably contains 10-80 per cent by volume of lower alkanol and 5-40 per cent weight/volume of alkali metal hydroxide, based on the water content, these two variables being chosen so that the distribution of hydroperoxides is less than 12 : 1, preferably less than 5 : 1 between the oxidate phase and the extraction mixture.  For the extraction of n-decane monohydroperoxides the extractant preferably contains 50 per cent by volume of methanol and 50 per cent by volume of 20 per cent weight/volume aqueous sodium hydroxide.  For the extraction of dimethyl and diethyl 1 : 2 : 3 : 4-tetrahydronaphthalene monohydroperoxides, the extractant preferably contains 50 per cent by volume of methanol and 50 per cent by volume of 40 per cent weight/volume aqueous sodium hydroxide.  Potassium hydroxide may be used instead of sodium hydroxide.  For the extraction of aromatic hydroperoxides it is advantageous to dilute the oxidate with a lower paraffin solvent. The extraction may be performed at any temperature, e.g. room temperature.  The extraction process may be preceded by preliminary extractions with water, with aqueous alkali and with aqueous lower alkanol to remove di- and higher hydroperoxides, hydrogen peroxide, esters, ketones, acids, alcohols and glycols, so that the subsequent extraction process yields mono-hydroperoxides of high purity.  The hydroperoxides obtained in the extraction mixture may be recovered by extraction into benzene, toluene, methyl isobutyl ketone, chloroform or carbon tetrachloride, preferably after neutralization, e.g. with carbon dioxide, and thence by evaporation of the solvent if desired.  In examples: (1) n-decane is autoxidized at 145 DEG  C. until 0.4-0.45 mole. of oxygen per litre of decane has been absorbed, the oxidate is given three preliminary single stage batch extractions with water and two with aqueous sodium hydroxide, and is then extracted with a mixture of methanol and aqueous sodium hydroxide, and after treating the extraction mixture with carbondioxide, the decane mono-hydroperoxides are extracted therefrom with benzene; (2) and (3) a decane oxidate is extracted with water, with aqueous sodium hydroxide, with methanol and then with aqueous methanolic sodium hydroxide and worked up as in (1); (4) 2-methyl undecane is antoxidized at 140 DEG  C. and is then given two extractions with water, two with aqueous sodium hydroxide, and one with aqueous ethanol, followed by two extractions with a mixture of ethanol and aqueous sodium hydroxide, the extraction mixture being treated with carbon dioxide and extracted with benzene to recover 2-methyl undecane mono-hydroperoxide; (5) m-diisopropylbenzene monohydroperoxide in m-diisopropylbenzene is extracted with a mixture of methanol and aqueous sodium hydroxide; (6) 1 : 4-diethyl-1 : 2 : 3 : 4-tetrahydronaphthalene is oxidized as described in Specification 786,341, extracted with aqueous sodium hydroxide, diluted with light petroleum and then extracted with aqueous methanolic sodium hydroxide; the extract is washed with light petroleum, diluted with water, neutralized with carbon dioxide and then extracted with light petroleum; (7) 1 : 4-dimethyltetrahydronaphthalene is treated as in (6); (8) 1 - ethyltetrahydronaphthalene and (9) 1-methyl-3-phenylindane are oxidized to the hydroperoxides and worked up as in (6).