Peroxides in ether

Monitor stock, e.g. temperature, pressure, reaction, inhibitor content, degradation of substance, deterioration of packaging or containers/corrosion, leakages, condition of label, expiry date, undesirable by-products (e.g. peroxides in ethers) Spillage control bund, spray, blanket, containment. Drain to collection pit Decontamination and first-aid provisions, e.g. neutralize/destroy, fire-fighting Contain/vent pressure generated to a safe area... 

Trialkyltin methoxides react with anhydrous hydrogen peroxide in ether to give the rather unstable bis(trialkyltin) peroxides, RsSnOOSnRs (214). Under the same conditions, dialkyltin dimethox-ides give polymeric peroxides, (RzSnOO), but, if an aldehyde is present, monomeric peroxides of the following structure are obtained (215). 

A sample of the peroxide in ether, prepared according to a published procedure [1], was being evaporated to dryness with a stream of air when it exploded violently. Handling the peroxide as a dilute solution at low temperature is recommended [2], See other diacyl peroxides... 

One or two attempts to reduce the diacyl peroxide in ether led to a moderately... 

The slow spontaneous oxidation of compounds in the presence of oxygen is termed autoxidation (autooxidation). This radical process is responsible for a variety of transformations, such as the drying of paints and varnishes, the development of rancidity in foodstuff fats and oils, the perishing of rabber, air oxidation of aldehydes to acids, and the formation of peroxides in ethers. 

Triphenylphosphine PhsP (M.W. 262.29, m.p. 79-81°, b.p. 377°) reacts spontaneously with all kinds of organic peroxides in ether, petroleum ether or benzene and extracts one atom of oxygen per peroxide bond [290]. It also extrudes sulfur and converts thiiranes to alkenes [291], and performs other reductions [292]. 

Treatment of carbazole with potassium permanganate in acetone (or nickel peroxide in ether ) gave mainly 9,9 -bicarbazole 9 (23%) together with the trimer 10 (8%). In the potassium permanganate oxidation,... 

A) Anon, IEC, NewEdn, 14, 305(1936)(Peroxide formation in ethers and a test for peroxides in ether) [Procedure a) Add 10ml ether (sample to test) to 150ml of 2N sulfuric acid soln, followed by 3 drops of 1% soln of Amm molybdate (a catalyst to favor the liberation of dine) and 15ml of 10% KI soln. Shake well aiiJ allow to stand for 15 mins b) Titrate the liberated iodine with 0.05N Na thiosulfate and shake well after each addn until near discoloration of soln c) Add a few cc of starch soln and continue titration until disappearance of blue color]... 

Tetramethyloxetan-2-one is solvolyzed, with recyclization, by means of hydrogen peroxide in ether containing sulfuric acid, to give a 60% yield of the corresponding peroxylactone in high purity (equation 23) (72S616). 

Peroxides in ether solvents. This is one of the commonest causes of explosions in organic chemistry laboratories. Simple dialkyl ethers such as diethyl ether and di-isopropyl ether, and cyclic ethers such as 1,4-dioxane and tetrahydrofuran, form less volatile peroxides on exposure to air and light. If therefore one of these solvents is purified by distillation, the peroxide content in the residue is progressively increased and eventually a violent explosion may occur. In view of this (i) such solvents should not be stored for long periods or in half empty bottles containers should be of dark glass (ii) before the solvents are distilled a peroxide test should be carried out, and, if positive, the peroxide must be removed (Section 4.1.11, p. 402 and Section 4.1.75, p. 404) and (iii) since purified ethers in contact with air rapidly peroxidise again (10 minutes in the case of tetrahydrofuran) they should be retested for peroxides and purified if necessary immediately before use. 

The following procedure is recommended for checking and neutralizing the peroxides in ethers before their distillation ... 

Diacyl peroxides are good agents for the alkylation of p-benzo- and 1,4-naphthoquinones having a free position in the quinoid ring, particularly when the normal- or iso-alkyl chains are desired (3( 60%). The method has been widely applied in the synthesis of 2-hydroxy-l,4-naphthoquinones substituted in the 3-position. The procedure consists in adding slowly a solution of the diacyl peroxide in ether to a solution of the quinone in acetic acid at 90-95°. 

Perkin condensation. 392 Peroxides in ethers, 284 Phase transfer catalyst, 128 Phenanthrene, 198 Phenetole, 278, 431 Phenolphthalein. 444 Phenols, acidity of, 433 summary of chemistry. 441 Phenylhydrazine, 315 Phosgene, 4, 369 Phthalic acid, 343 Phthalimide. 403 Pi bond, 15 Picoline, 454, 457 Picric acid, 432... 

A solution of anhydrous hydrogen peroxide in ether ( 2.5 M) is obtained by repeated extraction of 30% aqueous hydrogen peroxide with ether and drying of the ether extracts over anhydrous magnesium sulfate. The hydrogen peroxide content is determined by iodometric titration [726]. 

If dialkyltin dialkoxides are treated with 98% hydrogen peroxide in ether, insoluble cyclic or linear dialkyltin peroxides (R2SnOO) are formed. These are thermally more stable than the bistrialkyltin peroxides, R3SnOOSnR3, and lose about half their peroxide content in one month at room temperature. If the reactions are carried out in the presence of an aldehyde, l,2,4-trioxa-3-stannolanes are formed, together perhaps with some oligomeric material.132... 

I-Alkoxyhydroperoxides. Rieche and Bischoff preffared anhydrous hydrogen peroxide by treating a solution of 60 g. of 84% peroxide in ether with anhydrous sodium sulfate and magnesium carbonate. After 2 days the mixture was filtered and an aliquot titrated. One equivalent of an acetal was added to 1 equivalent of the ethereal solution, and the mixture was heated cautiously at 70°. The ether was allowed to distil to give a mixture of the acetal and the anhydrous reagent. After a reaction period of about 15 hrs. at 70°, the 1-alkoxyhydroperoxide was isolated in yields in the range 40-70%. 

The reaction of cyclohexanone with hydrogen peroxide in ether has been shown to yield (7) or the mono or bishydroperoxide according to the ratio of the reactants."... 

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