3- Chlorobenzoyl peroxide

In the case of the thermolysis of uns5mrmetrical diacyl peroxides, R—CO—O2 —CO—Ar, with negatively substituted phenyl groups e.g. Ar = 3-chlorophenyl), there is a moderate increase in reaction rate with increasing solvent polarity. They are generally considered to involve ion-pair intermediates e.g. R 02C—Ar), formed via dipolar activated complexes. A typical example is that of endo- and evo-(2-norbomyl)formyl 3-chlorobenzoyl peroxide /ri(CH3CN)/A i (cyclohexane) = 320 for the exu-reactant [563]. 

C6Hs)3C -I- bis-(3-chlorobenzoyl)peroxide Dissociation of (C6H5)3CC(CsH5)3... 

Figure 2.20. Rates of catalysed and uncatalysed polymerisation of styrene at different temperatures. Catalysts used (all at 0.0133 moleA). A, bis-(2,4-dichlorobenzoyl) peroxide B, lauroyl peroxide C, benzoyl peroxide D, bis-(/)-chlorobenzoyl) peroxide E, none. (After Boundy and Boyer )...

Chemical Designations - Synonyms Bis-(p-chlorobenzoyl)peroxide p-Chlorobenzoyl Peroxide p,p -Dichlorobenzoyl Peroxide Di-(4-chlorobenzoyl)peroxide Cadox PS Chemical Formula (p-ClCsH COOIj. 

Since the benzene emission in the thermal decomposition of benzoyl peroxide results from radical transfer by the phenyl component of a benzoyloxy-phenyl radical pair, phenyl benzoate produced by radical combination within the same pair should appear in absorption. A weak transient absorption has been tentatively ascribed to the ester (Lehnig and Fischer, 1970) but the complexity of the spectrum and short relaxation time (Fischer, personal communication) makes unambiguous assignment difficult. Using 4-chlorobenzoyl peroxide in hexachloro-acetone as solvent, however, the simpler spectrum of 4-chlorophenyl 4-chlorobenzoate is clearly seen as enhanced absorption, together with... 

In the decomposition of benzoyl peroxide, the fate of benzoyloxy radicals escaping from polarizing primary pairs remains something of a mystery. Benzoic acid is formed but shows no polarization in and C-spectra, and the carboxylic acid produced in other peroxide decompositions behaves similarly (Kaptein, 1971b Kaptein et al., 1972). Some light is shed on the problem by studies of the thermal decomposition of 4-chlorobenzoyl peroxide in hexachloroacetone containing iodine as... 

Fig. 8. Product yields and polarization (100 MHz) in the thermal decomposition (126°C) of 4-chlorobenzoyl peroxide (0-1 m) in hexachloroacetone containing iodine and water. Curve A, 4-ohlorobenzoic acid ([HjO], ca. 0-03 M) Curve B, p-chloroiodobenzene ([H2O], CO. 0-03 m) Curve C 4-chIorobenzoic acid ([HaO], ca. 1-6 m) Curve D, p-chloro-iodobenzene ([H O], ca. 1-6 m) Curve E, maximum intensity of emission from p-chloro-iodobenzene (O, co. 0-03 m H2O , ca. 1-6 M H2O). Data of Blank and Fischer, 1971b.

Another differential reaction is copolymerization. An equi-molar mixture of styrene and methyl methacrylate gives copolymers of different composition depending on the initiator. The radical chains started by benzoyl peroxide are 51 % polystyrene, the cationic chains from stannic chloride or boron trifluoride etherate are 100% polystyrene, and the anionic chains from sodium or potassium are more than 99 % polymethyl methacrylate.444 The radicals attack either monomer indiscriminately, the carbanions prefer methyl methacrylate and the carbonium ions prefer styrene. As can be seen from the data of Table XIV, the reactivity of a radical varies considerably with its structure, and it is worth considering whether this variability would be enough to make a radical derived from sodium or potassium give 99 % polymethyl methacrylate.446 If so, the alkali metal intitiated polymerization would not need to be a carbanionic chain reaction. However, the polymer initiated by triphenylmethyl sodium is also about 99% polymethyl methacrylate, whereas tert-butyl peroxide and >-chlorobenzoyl peroxide give 49 to 51 % styrene in the initial polymer.445... 

Biphenyl-Diphenyl Ether Bis(Acetato)Dioxouranium Bis(2-Aminoethyl)Amine N, N-Bis(2-Aminoethyl) Ethylenediamine Bis(P-Chlorobenzoyl) Peroxide Bis(2-Chloroethyl) Ether Bis(2-Chloroethyl) Ether Bis(Dimethylthiocarbamyl) Disulfide Bis(Dimethylthiocarbamyl) Disulfide Bis(2-Ethylhexyl) Hydrogen Phosphate Bis-(2-Ethylhexyl)Hydrogen Phosphate Bis(2-Ethylhexyl) Phthalate Bis(2-Ethylhexyl)Sodium Sulfosuccinate Bis(2-(2-Hydroxyethoxy)Etlryl) Ether... 

Compound Name Cadmium Nitrate Cadmium Oxide Cadmium Sulfate Cyclohexanone Peroxide DI-(p-Chlorobenzoyl) Peroxide Tert-Butyl Hydroperoxide Aluminum Sulfate Calcium Phosphate Calcium Resinate... 

Di(chlorobenxoyl) Peroxide, Bis(chlorobenzoyl) Peroxide or Dichlorodibenzoyl Peroxide [called Bi s( c h lor-ben zoylj perox yd or Dichlor-dibenzoyl-peroxyd in Ger],... 

Di(m-cblorobenzoyl) Peroxide, crysts (from hydrocarbon solvs), mp 123° dec was prepd by reaction 3 chlorobenzoyl chloride in dry toluene with an excess of aq Na2 2 (Ref 4) Di(p chlorobenzoyl) Peroxide, crysts (from CS2), mp 142°dec explodes in a steel bomb when heated to 180° giving 4-4 -dichlorodiphenyl,... 

Of peracids, MCPBA and (+)-MPCA are used most often. Oxidation is usually carried out in aprotic solvents, mostly in CH2CI2, CHCI3, or with phase-transfer catalysis. Periluorinated oxaziridines are prepared in acetonitrile212,213. The acid side-product, m-chlorobenzoic acid, is insoluble in the solvent and the desired oxaziridine may be prepared in good yield. MCPBA, however, is expensive, and large-scale oxidations are sometimes contaminated with bis(m-chlorobenzoyl) peroxide, which complicates product purification206. 

Decomposition of Aromatic Acyl Peroxides. The decomposition of aromatic acyl peroxides in liquid aromatic compounds is similar to the decomposition of nitrosoacetylarylamines and appears to involve the intermediate formation of free radicals. When dibenzoyl peroxide is heated in benzene, biphenyl, benzoic acid, and small amounts of phenyl benzoate, p-terphenyl, and quaterphenyl are produced. 4 That the second component enters into the reaction is shown by the formation of 4-chlorobiphenyl from the decomposition of di-p-chlorobenzoyl peroxide in benzene 84 and of dibenzoyl peroxide in-chlorobenzene 86... 

DICHLOROBENZOIC ACID see DER600 p-DICHLOROBENZOL see DEP800 (-t-)-4.((3,4-DICHLOROBENZOYL)AMINO)-5-((3-METHOXYPROPTX)PENTYLA nNO)-5-OXOPENTANOIC ACID see LlllOO d,l-4-(3,4-DICHLOROBENZOYLAMINO)-5-(N-3-METHOXYPROPYLPENTYLAMINO)-5-OXO-PENTANOIC ACID see LlllOO DI-(4-CHLOROBENZOYL) PEROXIDE see BHM750... 

Di(o-chlorobenzoyl) Peroxide, crysts (from chlf + MeOH), mp 101-02°dec was prepd by oxidizing 2-chlorobenzoyl chloride with H2O2 in alkaline soln (Ref 3)... 

---