Patent GB-666371-A (GB)
Title: Process for the production of organic peresters and the peresters so produced
IPC: C07C409/38
Filed: 1949-10-10
Abstract: Organic per-esters are prepared by contacting at a temperature at which they are stable an organic methane-hydroperoxide having the general formula R3C-O-O-H, in which R represents one or more of the following: a hydrogen atom, an open-chain aliphatic hydrocarbon radical with or without any aryl substituents and an aryl group, but in which there are not more than two hydrogen atoms in the position indicated by R, and the halogen and hydroxyl substitution derivatives of such hydroperoxides, with a ketene or its dimer.  The process is preferably carried out at from about 0 DEG  C. to about 50 DEG  C., and in batchwise or continuous liquid phase operation.  The ketene is preferably added to a solution of the hydroperoxide in an inert solvent.  The ketene may be added in the form of its vapour or in solution in an inert solvent.  Inert solvents which are suitable include ethers such as diethyl ether, dipropyl ether and dioxane; esters such as methyl acetate, ethyl benzoate and isopropyl butyrate and hydrocarbons such as pentane, nonane and toluene.  The reaction is preferably effected under atmospheric pressure.  The reactants may be used in the proportions of from about 1 to 10 parts of the ketene to 10 to 1 parts of the hydroperoxide; equimolar amounts are preferred.  When hydroperoxides which are stable in the presence of inorganic acid are used, a trace of such acid may be used as catalyst.  In examples: (1) gaseous ketene is passed into tertiary-butyl hydroperoxide in presence of a trace of aqueous sulphuric acid over one hour at 0-30 DEG  C., yielding tertiary-butyl peracetate, isolated by diluting the reaction mixture with pentane, extracting the unreacted hydroperoxide with water and removing the solvents by vacuum distillation; (2) acetyl-ketene is passed into tertiary-butyl hydroperoxide in like manner, yielding tertiary-butyl acetyl per acetate; (3) gaseous ketene is passed into alpha-alpha-dimethyl benzyl hydroperoxide in cumene at between 0 DEG and 40 DEG  C. for one hour and the resulting alpha-alpha-dimethyl benzyl peracetate is isolated by removing unreacted hydroperoxide with dilute caustic soda and removing solvent by vacuum distillation; (4) bromo-tertiary-butyl peracetate is similarly prepared by passing ketene into bromo-tertiary-butyl hydroperoxide in cumene.  Reference is made to the production of esters of aryl-substituted per-acetic acids from the hydroperoxides and aryl-substituted ketenes, such as methyl, phenyl methyl peracetate and tertiary-butyl diphenyl peracetate.  Other hydroperoxide starting materials mentioned are 1-hydroxy heptyl-, oleyl-, 1-methyl octyl-, tetradecyl-, para-tolylmethyl-, mesityl-tertiary-butyl-, chloro-tertiary, butyl-, beta-bromo-tertiary-amyl-, and alpha-alpha-dimethyl - para - chlorobenzyl - hydroperoxides.  Additional examples of ketenes which may be used are dialkyl ketenes such as dimethyl ketene, methylethylketene, diisopropyl ketene and dodecyl ketene; diaryl ketenes such as diphenylketene, dibenzyl ketene, dimesityl ketene, phenyl-para-tolyl ketene, di-para-tolyl-ketene and mesitylphenyl ketene; aryl alkyl ketenes such as methyl benzyl ketene and ethyl phenyl ketene; aldoketenes such as mesityl ketene; diketenes such as acetyl ketene; and ketenes containing additional functional groups such as ethyl chloroketene and ethyl bromoketene.  Specification 640,192 is referred to.  The Specification as open to inspection under Sect. 91 includes the use, as starting materials, of hydroperoxides of the general formula R3C-O-O-H wherein R is hydrogen or an organic radical, which are capable of independent existence or are stable in the form of a solution in an inert solvent.  Additional examples illustrate the production of (1) tertiary-butyl diphenyl peracetate by addition of a solution of diphenyl ketene in pentane to tertiary-butyl hydroperoxide containing a trace of sulphuric acid; (2) tertiary-amyl phenylmethyl peracetate similarly from phenyl methyl ketene and tertiary-amyl hydroperoxide, and (3) tertiary-butyl ethyl chloroperacetate by passing gaseous ethyl chlor ketene into tertiary butyl hydroperoxide in cumene.  Ethyl carbophenoxyketene is mentioned as a further reagent.  This subject-matter does not appear in the Specification as accepted.