Ethyl tert-butyl peroxide

Aliphatic amines have much less effect on the later reactions of the gas-phase oxidation of acetaldehyde and ethyl ether than if added at the start of reaction. There is no evidence that they catalyze decomposition of peroxides, but they appear to retard decomposition of peracetic acid. Amines have no marked effect on the rate of decomposition of tert-butyl peroxide and ethyl tert-butyl peroxide. The nature of products formed from the peroxides is not altered by the amine, but product distribution is changed. Rate constants at 153°C. for the reaction between methyl radicals and amines are calculated for a number of primary, secondary, and tertiary amines and are compared with the effectiveness of the amine as an inhibitor of gas-phase oxidation reactions. 

Action of Diethylamine on Decomposition of Ethyl tert-Butyl Peroxide. The rate of decomposition of ethyl ferf-butyl peroxide is decreased by adding diethylamine (Figure 7), and the yield of products is altered (Table II). Again, the yield of methane is increased at the expense of ethane and f erf-butyl alcohol is increased at the expense of acetone. Ethanol and acetaldehyde are formed in considerably greater amounts. The yields of carbon monoxide and methyl ethyl ketone are decreased. 

Even large amounts of aliphatic amines do not alter the rate of decomposition of tert-butyl peroxide, but they do slow down the rate of decomposition of ethyl tert-butyl peroxide. 

This retardation of ethyl tert-butyl peroxide decomposition may possibly be caused by competition between the inhibitor and the peroxide for methyl radicals (Reactions 1-4). 

C14H30O4S 2-(octylsulfonyl)ethyl tert-butyl peroxide 83073-73-8... 

Materials. Methylene 4,4 -diphenyldiisocyanate (MDI, Mobay) was recrystallized from cyclohexane. Toluenediisocyanate (TDI— represents mixture of 2,4- and 2,6-isomers in 80/20 ratio), p-toluidine (Aldrich) and aniline (Aldrich) were purified by vacuum distillation before use. Diphenylmethane, tert-butyl peroxide (TBP), 4-bromoaniline, butyl lithium in hexane, and ethyl chloroformate, were obtained from Aldrich and used as received. Spectrograde tetrahydrofuran (THF) and benzene from Burdick and Jackson were used as received. Poly(tetramethylene ether glycol) with MW 1000 was obtained from polysciences and dehydrated under a rough vacuum at 50 °C for 24 h. 

Disproportionation reaction 7 might be expected to be thermoneutral in the gas phase and perhaps less so in the liquid phase where there is the possibility of hydrogen-bonding. Only for gas phase dimethyl peroxide is the prediction true, where the reaction enthalpy is —0.2 kJmoD. The liquid phase enthalpy of reaction is the incredible —61.5 kJmoD. Of course, we have expressed some doubt about the accuracy of the enthalpy of formation of methyl hydroperoxide. For teri-butyl cumyl peroxide, the prediction for thermoneutrality is in error by about 6 kJmor in the gas phase and by ca 9 kJmoD for the liquid. The enthalpy of reaction deviation from prediction increases slightly for tert-butyl peroxide — 14kJmol for the gas phase, which is virtually the same result as in the liquid phase, — 19kJmol . The reaction enthalpy is calculated to be far from neutrality for 2-fert-butylperoxy-2-methylhex-5-en-3-yne. The enthalpies of reaction are —86.1 kJmoD (g) and —91.5 kJmol (Iq). This same species showed discrepant behavior for reaction 6. Nevertheless, still assuming thermoneutrality for conversion of diethyl peroxide to ethyl hydroperoxide in reaction 7, the derived enthalpies of formation for ethyl hydroperoxide are —206 kJmoD (Iq) and —164 kJmoD (g). The liquid phase estimated value for ethyl hydroperoxide is much more reasonable than the experimentally determined value and is consistent with the other n-alkyl hydroperoxide values, either derived or accurately determined experimentally. 

Karpel Vel Leitner N, Papailhou AL, Croue JP, Peyrot J, Dore M. Oxidation of methyl tert-butyl ether (MTBE) and ethyl tert-butyl ether (ETBE) by ozone and combined ozone/hydrogen peroxide. Ozone Sci Eng 1994 16 41-54. 

Epoxynovolak resin and BPA/DC-BMI prepolymer, tert.butyl peroxide and Zn acetate [106, 107] or 2-phenylimidazole and other catalysts [108] were filled with wollastonite. Carbon-fiber reinforced composites were obtained using a binder, which consisted of BPA/DC, BMI, an epoxynovolak, 2-ethyl-4-methylimidazole and an organic solvent [109]. A BPA/DC-BMI prepolymer in methylethylketone was mixed with middle-molecular-weight epoxide resin (Epikote 1001), 2-ethyl-4-methyl-imidazole, Zn acetate and triethylenediamine thermal shock resistant GRP was thus obtained [110]. 

Peroxid (2-Brom-ethyl)-tert.-butyl-E13/1, 396 (HgBr-Br)... 

With a high-temperature initiator such as di-tert-butyl peroxide, copolymers of 1-octene with allyl propionate or allyl butyrate have been prepared in sealed tubes. The reaction conditions included methyl ethyl ketone as a solvent, 0.05% di-tert-butyl peroxide heated in sealed ampoules at 200°C for 4 hr. The molecular weights of the product were in the range of 600 200 [62]. 

Preparation of Poly(vinyl ethyl ether) Using Di-tert-butyl Peroxide Initiator. . 247... 

METHYL ISOBUTYL KETONE n-PENTYL FORMATE n-BUTYL ACETATE sec-BUTYL ACETATE tert-BUTYL ACETATE ETHYL n-BUTYRATE ETHYL ISOBUTYRATE ISOBUTYL ACETATE n-PROPYL PROPIONATE CYCLOHEXYL PEROXIDE DIACETONE ALCOHOL 2-ETHYL BUTYRIC ACID n-HEXANOIC ACID 2-ETHOXYETHYL ACETATE HYDROXYCAPROIC ACID PARALDEHYDE... 

The b value for peroxides was not evaluated in the original publication, but we can do so here from the experimental enthalpies of vaporization that are available. There are three such for the alkyl hydroperoxides 35 kJmor for methyl hydroperoxide, 43.1 kJmol for ethyl hydroperoxide and 47.7 kJmol for tert-butyl hydroperoxide. The corresponding b values are 27.3, 30.8 and 29.8 kJmol , respectively. The mean value, 29.0 4=... 

Materials. Chemically pure solvents and reagent grade ceric ammonium nitrate were used as received. Cumene hydroperoxide was purified via the sodium salt. Lucidol tert-butyl hydroperoxide was purified by low temperature crystallization. Tetralin hydroperoxide, cyclohexenyl hydroperoxide, and 2-phenylbutyl-2-hydroperoxide were prepared by hydrocarbon oxidation and purified by the usual means. 1,1-Diphenyl-ethyl hydroperoxide and triphenylmethyl hydroperoxide were prepared from the alcohols by the acid-catalyzed reaction with hydrogen peroxide (10). 

Free cydohexene from peroxides by treating it with a saturated solution of sodium bisulphite, separate, dry and distil collect the fraction, b.p. 81-83°. Mix 8 2 g. of cydohexene with 55 ml. of the reagent, add a solution of 15 mg. of osmium tetroxide in anhydrous tert.-butyl alcohol and cool the mixture to 0°. Allow to stand overnight, by which time the initial orange colouration will have disappeared. Remove the solvent and unused cydohexene by distillation at atmospheric pressure and fractionate the residue under reduced pressure. Collect the fraction of b.p. 120 140°/15 mm. this solidifies almost immediately. Recrystallise from ethyl acetate The yield of pure cts-1 2-cydohexanediol, m.p. 96°, is 5-0 g. 

The nature of the initiation step, which may occur in a variety of ways, is not known in all cases. Commonly used ethers such as ethyl ether, isopropyl ether, tetrahydrofuran, and />-dioxane are particularly prone to form explosive peroxides on prolonged storage and exposure to air andlight (see Peroxides and PEROXY COMPOUNDS, ORGANIC), and should contain antioxidants (qv) to prevent their build-up. One of the exceptions to the peroxide forming tendency of ethers is methyl tert-5 ky ethers such as methyl tert-butyl ether [1634-04-4] (MTBE) and ter1-axn.y methyl ether [994-05-8] (TAME). Both have shown little tendency if any to form peroxides (2,8). 

Alkyl hydroperoxides, including ethyl hydroperoxide, cuminyl hydroperoxide, and tert-butyl hydroperoxide, are not used by V-BrPO to catalyze bromination reactions [29], These alkyl hydroperoxides have the thermodynamic driving force to oxidize bromide however, they are kinetically slow. Several examples of vanadium(V) alkyl peroxide complexes have been well characterized [63], including [V(v)0(OOR)(oxo-2-oxidophenyl) salicylidenaminato] (R = i-Bu, CMe2Ph), which has been used in the selective oxidation of olefins to epoxides. The synthesis of these compounds seems to require elevated temperatures, and their oxidation under catalytic conditions has not been reported. We have found that alkyl hydroperoxides do not coordinate to vanadate in aqueous solution at neutral pH, conditions under which dihydrogen peroxide readily coordinates to vanadate and vanadium( V) complexes (de la Rosa and Butler, unpublished observations). Thus, the lack of bromoperoxidase reactivity with the alkyl hydroperoxides may arise from slow binding of the alkyl hydroperoxides to V-BrPO. 

The methyl radical is formed from (3-cleavage of the r-butoxyl radical derived from di-t-butyl peroxide (cat.), and it reacts with ethyl styrenyl sulfone to generate an ethanesulfonyl radical and trans-(3-methylstyrene. The ethyl radical formed from (3-cleavage of the ethanesulfonyl radical, at last, reacts with alkyl iodide (71) via SH2 pathway to produce an alkyl radical and ethyl iodide. Here, the alkyl radical should be more stable than the ethyl radical. Therefore, alkyl radicals should be sec- or tert-alkyl radicals. The formed alkyl radical reacts with ethyl styrenyl sulfone to give addition-elimination product (72), together with ethanesulfonyl radical as a radical chain precursor. 

Other peroxides—2,6-dichlorobenzoyl peroxide lauroyl peroxide, tert-butyl hydroperoxide, and methyl ethyl ketone peroxide—are also highly effective for the free radical reaction at low temperatures. On the other hand, azobisisobutyronitrile (AIBN) is ineffective. Hence, the mechanism cannot be simple, free radical formation which then initiates polymerization. 

Peroxid tert.-Butyl-(2-hydroxy-ethyl)- VI/Ia,l, 386 E13/1, 376/378 (Oxiran 4- R-0 - OH) Propan l,l-Dimethoxy-2-hydroxy-2-methyl- E14a/I. 766 (R2CH-CHO + R-OH/ Elektrol.)... 

Peroxid (Amino-ethyl-phosphonyl)-tert.-butyl- E13/1, 947 (Cl 0-0R/NH2)... 

Peroxid tert.-Butyl-(2-trifluoraceto-xymercuri-ethyl)- E13/1, 322 (Peroxymercurierung)... 

Ethyl-2-oxo-4-propyl-XII/2, 36 Peroxid tert.-Butyl-(phosphinyl)-E13/1, 940 (Cl - O-OR) Phosphanoxid Acetoxymethyl-butyl-methyl- E2, 48 (P-Oxigenier.) Phosphonsaure... 

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