Hexachloroacetone

Into a 1-1. three-necked flask, fitted with a mechanical stirrer, a reflux condenser, a thermometer (Note 1), and a dropping funnel, is placed a solution of 265 g. (1 mole) of hexachloroacetone (Note 2) in 400 ml. of hexane (Note 3). To the stirred solution is added, dropwise, 93 g. (1 mole) of aniline (Note 4) over a period of 35-40 minutes. During this time the temperature rises to about 55°. After the addition is complete, stirring is continued at 65-70° for 45 minutes. 

Commercial hexachloroacetone (Allied Chemical Corporation) was distilled and the fraction boiling at 93-97°/24 mm. was used. 

Trichloroacetanilide has been prepared from hexachloroacetone and aniline, from trichloroacetyl chloride and aniline, by the action of aniline magnesium iodide on ethyl trichloroacetate, by heating N-phenyltrichloroacetimidyl chloride with dilute methanol, and from trichloroacetic acid and aniline in the presence of phosphorus oxychloride. ... 

Heptadecanoic acid, 43,39 Heptane, 1,1,1-trifluoro, 41, 104 Heptanoic acid, 3-methyl-, 41, 60 Heptanoic add, reaction with sulfur tetrafluoride, 41,104 1-Hepten4-ol, 4,6-dimethyl-, 41,30 Hexachloroacetone, reaction with aniline to form ,M,a-trichloroacet-anilide, 40,103... 

Hexachloroacetone, reaction with a variety of amines to form the corresponding ar,at,a-tri-chloro-acetamides, 40,104... 

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.

Triphenylphosphine dichloride exhibits similar reactivity and can be used to prepare chlorides.18 The most convenient methods for converting alcohols to chlorides are based on in situ generation of chlorophosphonium ions19 by reaction of triphenylphosphine with various chlorine compounds such as carbon tetrachloride20 or hexachloroacetone.21 These reactions involve formation of chlorophosphonium ions. 

Another mechanism for alkanone-sensitized photodehydrochlorination comprises Norrish type I scission of the ketone, followed by ground-state reactions of radicals (19). However, the evidence for such a mechanism is based on experiments that were carried out in the vapor phase (19). Initiation of the photodegradation of PVC by hexachloroacetone has been suggested to involve the abstraction of hydrogen from the polymer by radicals resulting from the photolysis of the ketone s carbon-chlorine bonds (22). 

The scope of the reaction of triphenylphosphine/hexachloroacetone with allylic alcohols has been studied. Primary and some secondary alcohols such as 1 and 2 give good yields of unrearranged halides. Certain other alcohols, such as 3 and 4, give more complex mixtures. Discuss structural features which are probably important in determining how cleanly a given alcohol is converted to halide... 

Halogenated allenes undergo dimerization more easily and require milder temperatures. A convenient source for tetrachloroallene and its dimer 4 is the reaction of hexachloroacetone with triphenylphosphane. Under these conditions the allene is formed at — 70 °C but undergoes spontaneous dimerization when warmed to room temperature.24... 

Hexachloroacetone is fluorinated87 over potassium tetrafluorocobaltate(III) at 230°C. As with nonchlorinated ketones (Section 25.1.1.3.), no ketonic products are detected, and low yields of trichlorofluoromethane, methyl dichlorofluoroacetate (the reaction mixture is worked up by methanol treatment) and methyl trichloroacetate are isolated. 

It was postulated that the primary processes for the photolysis of hexachloroacetone were of types A and B, analogous to those observed for acetone itself as in reactions... 

Some support is given to this hypothesis by the fact that at higher temperatures the quantum yield of CO rises and becomes dependent upon the hexachloroacetone concentration and upon the light intensity, these effects being interpreted as the result of the thermal dissociation of a CChCO radical. However, no products such as hexachlorobiacetyl, which could arise from the intervention of the hexachloroacetyl radical, have been identified. 

The hexachloroethane is assumed to arise by the combination of CC13 radicals and the carbon tetrachloride by the abstraction of a chlorine atom from the hexachloroacetone by the CCh radicals. 

The rate function was shown to vary with light intensity or energy absorbed and also with the hexachloroacetone concentration, rising with the amount of energy absorbed (as measured by the amount of CO formed) and decreasing with increase in hexachloroacetone pressure. An explanation advanced for this phenomenon is that there is a further alternative primary step in which a C-Cl bond is ruptured with the formation of chlorine atoms. These react with CCI3 radicals and increase the rate of formation of carbon tetrachloride. 

A much more elaborate reaction scheme is postulated by Haszeldine and Nyman46 on the basis of three qualitative experiments to explain the liquid phase photolysis of hexachloroacetone. The rate of photolysis is extremely slow in the liquid phase, and the only products identified were trichloroacetyl chloride and octachloropropane. These are considered to arise by the following sequence of reactions in which the products of two competing primary steps interact. 

The very slow rate of photolysis of hexachloroacetone in the liquid phase is attributed to cage effects and recombination of the primary radicals. This is supported by the fact that the rate of disappearance of hexachloroacetone is accelerated by the addition of oxygen which would combine with the radicals as they were formed. A second consequence of... 

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