Oxidation in benzene solution

The reaction vessel is attached to the high-vacuum system, and the phosphorus trichloride transferred to it without loss and without risk. Further to reduce the hazards, a powerful magnetic stirrer is employed. The ethylphosphonous dichloride is then oxidized in benzene solution in a vessel connected directly to the vacuum system. 

Figure 1. Chemiluminescence exhibited by methyl ethyl ketone oxidation in benzene solution at 60°C. Arrow shows time of adding initiator Y...

The reaction rates for forming the products of methyl ethyl ketone oxidation in benzene solution, by the unimolecular and bimolecular routes of R02 conversion, are shown in Table VI. The yield of products formed by the bimolecular route decreases and that for the unimolecular route increases with dilution of methyl ethyl ketone by benzene. 

Oxidation of 2.6-dimethylphenol with silver oxide in benzene solution has been shown by Lindgren (58), to also yield a low molecular weight ( 2000) polyether in low yield as well as the diphenoquinone. 

This last possibility appeared to offer the most fruitful line of investigation. Therefore, we decided to determine what kinds of structural features would confer unusual free radical stability on simple model phenols which had been oxidized. Several phenols were oxidized in benzene solution by one-electron oxidants such as Pb02, alkaline ferricyanide,... 

I wish to thank J. C. Pew of the Forest Products Laboratory, Madison, Wis. for providing the phenols which were oxidized in benzene solution, Raymond E. Hansen of the Institute for Enzyme Research, Madison, Wis. for determining the EPR spectrum of syrinoxyl, and Theodore Scheffer of the Forest Products Laboratory, Madison, Wis., who directed the inoculation of wood with test fungi. 

Cycloaddition is the major mode of photoreaction between ethylenes and naphthalenes, and the product (58) from (3-naphthol and acrylonitrile has been photo-oxidized in benzene solution in the presence of mercuric oxide and iodine to give (59) in 40% yield." Formation of (59) involves a novel rearrangement and provides a convenient two-step entry into homotropones. 

Poly(styryl)lithlum (Hi=2400) was terminated with ethylene oxide In benzene solution at 25 C as shown In Equation 2. The GPC reten-... 

The cyanopyrazole is the minor product when R = H or Me, a yield of 20—25% of the 3-cyanocyclopropane is obtained [149]. One of the products of irradiating 5-methylpyrimidine N-oxide in benzene solution is the nitrile (61) which is converted to 2-cyanopropanal by acid [150]. 

The four stereoisomers (only one enantiomer is reported) are listed below with the relative yields obtained in the co-oxidation in benzene solution. 

Treatment of Fe3(CO)i2 with pyridine JV-oxide in benzene at room temperature gives the brown pyrophoric [Fe(CsH5NO)4][Fe4(CO)i3] IS). Irradiation of iron pentacarbonyl with dimethylsulfoxide in benzene solution at 80° C gives the red-black, slightly air-sensitive [Fe(Me2SO)e] [Fe4(CO) 13] 18). Irradiation of iron pentacarbonyl with triphenylphosphine oxide or triphenylarsine oxide in benzene solution at 80° C gives dark red materials formulated as [Fe((/>3PO)2][Fe2(CO)g] and [Fe( 3AsO)3][Fe2 (CO)g], respectively 18). The apparently low coordination numbers of two or three for the cationic iron atoms in these two compounds seem peculiar. 

The rate of dimerization of nitrile A-oxides is strongly influenced by the nature of R. When R = Cl, Br, CO2 alkyl or COR, the nitrile A-oxide cannot be isolated nor obtained in solution for any appreciable time. Table 11 gives the approximate time required for complete dimerization of some nitrile A-oxides (335) to furoxans (336) in benzene solution at 18 °C (70E1169). Evidently, steric and electronic effects dramatically increase the stability... 

The intermediacy of dipolar species such as 186 has been demonstrated by reaction of enamines with 2-hydroxy-1-aldehydes of the aromatic series (129). The enamine (113) reacts in benzene solution at room temperature with 2-hydroxy-1-naphthaldehyde to give the crystalline adduct (188) in 91 % yield. Oxidation with chromium trioxide-pyridine of 188 gave 189 with p elimination of the morpholine moiety. Palladium on charcoal dehydrogenation of 189 gave the known 1,2-benzoxanthone (129). 

Nitroso-5//-dibenz[/>,/]azepine (9, R = NO) is relatively stable to photolysis under argon, whereas in benzene solution in the presence of oxygen, irradiation induces an oxidative Fischer -Hepp-type rearrangement to 2-nitro-5//-dibenz[6,/]azepinc (10, R = N02), accompanied by ring contraction to acridine-9-carbaldehyde184 (see also Section 3.2.2.4.). 

Epoxyeyclohexanone has been prepared in 30% yield4 by epoxi-dation of 2-cyclohexen-l-one with alkaline hydrogen peroxide, using a procedure described for isophorone oxide (4,4,6-trimethyl-7-oxabicyclo[4.1.0]heptan-2-one).5 A better yield (66%) was obtained using f r/-butyl hydroperoxide (1,1-dimethylethylhydroperoxide) and Triton B in benzene solution.6 The procedure described here is simple and rapid. 

Synthesis of comb (regular graft) copolymers having a PDMS backbone and polyethylene oxide) teeth was reported 344). These copolymers were obtained by the reaction of poly(hydrogen,methyl)siloxane and monohydroxy-terminated polyethylene oxide) in benzene or toluene solution using triethylamine as catalyst. All the polymers obtained were reported to be liquids at room temperature. The copolymers were then thermally crosslinked at 150 °C. Conductivities of the lithium salts of the copolymers and the networks were determined. 

It may be pointed out that dehydration of p hydroxy esters with fused potassium hydrogen sulphate, acetic anhydride, phosphoric oxide or with thionyl chloride in benzene solution leads to ap-unsitturated esters containing some Py-unsaturated ester the proportion of the latter depends not only upon the structure of the ester but also upon the dehydrating agent used. I>ehydration occasionally occurs during the reaction itself or upon attempted distillation. 

Larger substituents or fewer Si-H groups lead to compounds that are more stable and which may be distilled in air, for example, c-C6HuSiH3 and Bu"3SiH (11). Although Ph3SiH is stable in air, it is oxidized by 02 in benzene solution in the presence of benzoyl peroxide... 

Oxidation of evermicose (122) with bromine yielded a mixture of y- and <5-lactones, which was directly acetylated. Refluxing the acetate in benzene solution in the presence ofp-toluenesulfonic acid gave (176) a mixture of the unsaturated lactones 131 and 132. In related work, Ganguly and Saksena (177) obtained an enonolactone by oxidation of D-nogalose with Jones reagent, followed by -elimination promoted by piperidine. Similarly, L-no-galose gave the enantiomeric lactone. 

The simplest method for preparing alkylene oxides involves the use of benzoyl peroxide (Prileschaiev). In absolute ether or, still better, in benzene solution, it is broken by sodium ethoxide into the sodium salt of perbenzoic acid and ethyl benzoate.1... 

CH2)2L0) were prepared. - " Such compounds can be oxidized with lead dioxide to N-picryl-9-aminocarbazyls (133). These black species are dehydrogenating agents though stable in dry chloroform the transformation of violet-black color into orange in benzene solution suggests that they... 

Figure 1. Oxidation products of acrolein in benzene solution at 35°C.

Figure 3. Rate of oxygen absorbed (mole X 10/mole AL/hr) and molar extinction coefficient (e) at 600 m during oxidation of acrolein in benzene solution at 35°C.

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