Trichloromethyl compounds

Similar behaviour is found with the analogous trichloromethyl compound but the hemiorthoester structure is less stable. The monotrifluoroacetates of isobutylene glycol and ethylene glycol exist wholly as esters and the cyclic hemiorthoesters cannot be detected. Compound [12] was reported to be formed when N,N-dimethyltrifluoroacetamide is added to a solution of potassium t-pentoxide in methylcyclohexane or isooctane (Fraenkel and Watson, 1975). 

The trichloromethyl group can be reduced to either the dichloro- or the monochloromethyl group by proper choice of the SSE 49 s With ammonium nitrate the dichloro compounds are formed in 64—94% yield, while with tetra-metliylammonium chloride as supporting electrolyte the monochloro derivatives are obtained in 63 to 95% yield. As trichloromethyl compounds are readily available by telomerization of olefins with CC14) this reduction opens a simple route to a, co-bifunctional aliphatic compounds. 

Transition metal complexes such as Fe(CO)5, in the presence of alcohols, cause a trichloromethyl compound to be selectively reduced to the corresponding dichloromethyl compound. This reaction has been reviewed elsewhere and is a very useful means of generating a dihalomethyl group130. Also chromium(II) complexes have been used to reduce aryl bromides131,132. Aromatic compounds such as benzene, aniline and pyridine have been used as hydrogen donors for the hydrodehalogenation of a-haloketones in the presence of tin(II) and iron(II) salts133. 

The use of carbon tetrachloride as a solvent in diketone irradiations is dangerous since intermediate radicals can abstract chlorine giving trichloromethyl radicals which can result in formation of complex mixtures. In a study 146) of the irradiation of 68 in CCI4, products included (inter alia) reduced 68 and the trichloromethyl compound 186. 

Metabolites of carbon tetrachloride may also give a positive result with tiiis test, but carbon tetrachloride is only partially metabolised to trichloromethyl compounds and the test may fail to detect this agent. If carbon tetrachloride poisoning is suspected, evidence of hepato-toxicity should be sought by carrying out appropriate serum-enzyme assays. 

The halogen of trihalides may be replaced analogously to that of mono- and gew-di-halides, no new considerations being involved. The usual reagents are slaked lime at 50°, alcoholic alkali hydroxides, acids, or iron(m) chloride in aqueous solution. Some trichloromethyl compounds are converted into carboxylic acids in excellent yield by heating them in chloroform in the presence of anhydrous iron(m) chloride whilst the appropriate amount of water is dropped in.549... 

Hydrolyses of perchloroalkylbenzenes and related chlorocarbons Nucleophilic attack on perchloroalkylbenzenes and related compounds dealkylations 294 Reductive condensations of perchlorotoluene and other highly chlorinated trichloromethyl chlorocarbons 298 Alkylation of trichloromethyl compounds with trialkyl phosphites A conversion of trichloromethyl groups into cyano groups 312... 

The reductive polycondensation of bis(trichloromethyl) compounds has been extended to other chlorocarbons (Ballester et ai, 1966). From per-chloro-p-tolyl and from perchloro-l,4-dipropenylbenzenes, the so-called... 

ALKYLATION OF TRICHLOROMETHYL COMPOUNDS WITH TRIALKYL PHOSPHITES... 

It is therefore most remarkable that the conversion of the trichloromethyl compound [72] into [73] can be achieved in very good yield with ammonia in aqueous THF at room temperature. As shown below, this reaction presumably starts from the red carbanion formed by proton abstraction, which easily eliminates chloride ion from the a-position forming violet carbanion through quinodimethane. Under the same reaction conditions, perchlorotoluene remains unaltered (M. Ballester and C. Fernandez-Llamazares, unpublished). 

R.K. Freidlina, R.G. Gasanov, N.A. Kuz mina and E.T. Chukovskaya, Transition Metal Carbonyls Combined with Hydrogen Donors as Initiators of the Radical Reduction of Trichloromethyl Compounds Russ. Chem. Rev., 1985, 662. ... 

Although 2-chloromethylpyridine cannot be prepared under the conditions described, chlorination in carbon tetrachloride in the presence of anhydrous sodium carbonate gives this product in good yield (65 per cent), with 5 per cent of 2-dichloromethylpyridine and some of the trichloromethyl compound i . This is easily the most convenient method for preparing the monochloro compound. 

The orthoformates [30] and orthobenzoates [31] are made from chloroform or trichloromethyl compounds by reaction with sodium alkoxides. 

Method 6. Polymerization of Trichloromethyl Compounds The reactions shown in Eq. (1-23) yield polymers of excellent thermal and chemical stability (2). Stannous or ferrous chlorides are catalysts in this reaction. Mixtures of dioxane and chloroform or dioxane and water are suitable solvents. The reactions are carried out under reflux ( 1(X)°C) for several hours. The use of an inert atmosphere is beneficial. High polymers with molecular weights up to 27,000 are obtained. 

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