Trichloromethane reaction

The gas phase chlorination of methane is a reaction of industrial importance and leads to a mixture of chloromethane (CH3CI) dichloromethane (CH2CI2) trichloromethane (CHCI3) and tetrachloromethane (CCI4) by sequential substitution of hydrogens... 

Halofluoroalkenes may be prepared by using fluorodihalomethanes or fluoro-halomethanes in olefination procedures similar to those descnbed above. Ruoro-trichloromethane treated with tris(dimethylamino)phosphine forms the corresponding phosphomum salt, which can then be used in the Wirtig procedure. The reaction depends on the nature of the solvent in tetrahydrofuran, little olefination if any occurs however, when benzomtrile is added to the mixture, ylide formation is promoted [50] (equation 48) (Table 19). 

Not many reactions between A-(l-haloalkyl)heteroarylium halides and anionic nucleophiles are reported in the literature. In trichloromethane or... 

A mixture of 22 parts of 1 -ethyl-1,4-dihydro-5H-tetrazol-5-one,45 parts of 1 -bromo-2-chloro-ethane,26 parts of sodium carbonate,0.3 part of potassium iodide and 240 partsof 4-methyl-2 pentanone is stirred and refluxed overnight with water-separator. The reaction mixture is cooled, water is added and the layers are separated. The aqueous phase is extracted three times with dichloromethane. The combined organic phases are dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using trichloromethane as eluent. The pure fractions are collected and the eluent is evaporated, yielding 28.4 parts (80%) of 1-(2-chloroethyi)-4-ethyl-1,4-dihydro-5H-tetrazol-5-one as a residue. 

A) A mixture of 333 parts of 4-(1 -piperazinyDphenol dihydrobromide, 11.2 parts of acetic acid anhydride, 42 parts of potassium carbonate and 300 parts of 1,4-dioxane is stirred and refluxed for 3 days. The reaction mixture is filtered and the filtrate is evaporated. The solid residue is stirred in water and sodium hydrogen carbonate is added. The whole is stirred for 30 minutes. The precipitated product is filtered off and dissolved in a diluted hydrochloric acid solution. The solution is extracted with trichloromethane. The acid aqueous phase is separated and neutralized with ammonium hydroxide. The product is filtered off and crystallized from ethanol, yielding 5.7 parts of 1 acetyl-4-(4-hydroxyphenyl)piperazine MP 181.3°C. 

The effect of sodium, potassium or ceiicium hydroxide on trichloromethane or bromoform in the presence of acetone gives rise to the following reaction, which is very exothermic and caused numerous accidents with detonations ... 

The reaction of a carboxylic acid with N,Af -carbonyldiimidazolellH33 (abbreviated as CDI), forming an imidazolide as the first step followed by alcoholysis or phenolysis of the imidazolide (second step), constitutes a synthesis of esters that differs from most other methods by virtue of its particularly mild reaction conditions.t41,[5] It may be conducted in two separate steps with isolation of the carboxylic acid imidazolide, but more frequently the synthesis is carried out as a one-pot reaction without isolation of the intermediate. Equimolar amounts of carboxylic acid, alcohol, and CDI are allowed to react in anhydrous tetrahydrofuran, benzene, trichloromethane, dichloromethane, dimethylformamide, or nitromethane to give the ester in high yield. The solvents should be anhydrous because of the moisture sensitivity of CDI (see Chapter 2). Even such unusual solvent as supercritical carbon dioxide at a pressure of 3000 psi and a temperature of 36-68 °C has been used for esterification with azolides.[6]... 

Nevertheless, new examples have also been reported of allenyl sulfoxides [101] and especially allenyl trichloromethyl sulfoxides [39, Y+-X = S(0)CC13] [102]. There have been many trials to use these sigmatropic rearrangements for the synthesis of diallenes (compare 40 — 42), e.g. the reaction of the diols 43 with trichloromethane-sulfenyl chloride 44 to the diallenes 45 (Scheme 7.7) [103]. 

Where we have reason to suspect the involvement of a particular species as a labile intermediate in the course of a reaction, it may be possible to confirm our suspicions by introducing into the reaction mixture, with malice aforethought, a reactive species which we should expect our postulated intermediate to react with particularly readily. It may then be possible to divert the labile intermediate from the main reaction pathway—to trap it—and to isolate a stable species into which it has been unequivocally incorporated. Thus in the hydrolysis of trichloromethane with strong bases cf. p. 46), the highly electron-deficient dichlorocarbene, CClj, which has been suggested as a labile intermediate (p. 267), was trapped by introducing into the reaction mixture the electron-rich species cis but-2-ene (11), and then isolating the resultant stable cyclopropane derivative (12), whose formation can hardly be accounted for in any other way ... 

Propanone reacts with trichloromethane in the presence of potassium hydroxide to give 1,1,1-trichloro-2-methyl-2-propanol. What is likely to be the mechanism of this reaction What further evidence could be gained to establish the mechanism (If you do not see a possible answer, refer to Section 14-7B for helpful information.)... 

Exercise 17-12 Trichloromethane (chloroform) at one time was synthesized commercially by the action of sodium hypochlorite on ethanol. Formulate the reactions that may reasonably be involved. What other types of alcohols may be expected to give haloforms with halogens and base ... 

In the somewhat related Reimer-Tiemann reaction, sodium benzenolate with trichloromethane in alkaline solution forms the sodium salt of 2-hydroxy-benzenecarbaldehyde (salicylaldehyde). The electrophile in this case probably is dichlorocarbene (Section 14-7B) ... 

Account for the formation of the by-product, 15, in the reaction of 4-methyl-benzenol with trichloromethane in alkali ... 

The reaction of 3-phenyloxetane (10) with nitric acid in dichloromethane and trichloromethane under anhydrous conditions has been investigated.35 Quantitative conversion into 2-(nitrophenyl)propane-l,3-diol dinitrates occurs. The substrate reacts through its majority hydrogen-bonded complexed form initially by a mixture of aromatic nitration and oxetane ring opening. The nitration, perhaps surprisingly, proceeds at a rate comparable to that of / -dichlorobenzene. 

Because we cannot control the chlorine free radicals produced in this reaction, we also obtain small amounts of other substituted products - CH2C12 (dichloromethane), CHC13 (trichloromethane or chloroform) and CC14 (tetrachloromethane) - by further reactions such as those shown below. 

The combustion of biomass, which invariably contains carbon and chloride, produces CHCI3, although the amount is much less than that recorded for CH3C1 and CH2C12 (283, 286) and is a minor emission source of CHC13 (<1%) (303-305) (Table 3.3). The high temperature (700°C) reaction of methane, HC1, and oxygen furnishes trichloromethane (232). 

Davis, D.D., Machado, G., Conaway, B., Oh, Y., Watson, R. (1976) A temperature dependent kinetic study of reaction of hydroxyl radicals with chloromethane, dichloromethane, trichloromethane and bromomethane. J. Chem. Phys. 65, 1268-1274. 

A mixture of 3-(2-bromoethyl)-2-methyl-pyrido[l,2-a]pyrimidin-4-one monohydrobromide, 3-furan-2-yl-methyl-(3H-imidazo[4,5-b]pyridine-2yl)-4-piperidinyl)-amine dihydrobromide, of sodium carbonate and of N,N-dimethylformamide was stirred and heated overnight at about 70°C. The reaction mixture was poured onto water. The product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (94 6 by volume), saturated with ammonia, as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from acetonitrile, yielding 3-(2-(4-((3-(2-furanylmethyl)-3H-imidazo[4,5-b]pyridin-2-yl)amino)-l-piperidinyl)ethyl)-2-methyl-4H-pyrido[l,2-a]pyrimidin-4-one melting point 202°C. 

A mixture of 13.4 parts of l-(4-methoxyphenyl)piperazine dihydrochloride, 7.9 parts of l-chloro-4-nitrobenzene, 10 parts of potassium carbonate and 90 parts of N,N-dimethylformamide is stirred and refluxed overnight. The reaction mixture is diluted with water and the product is extracted twice with trichloromethane. The residue is triturated in 4-methyl-2-pentanone. The product is filtered off and crystallized from 1,4-dioxane, yielding 10.5 parts (67%) of l-(4-methoxyphenyl)-4-(4-nitrophenyl)piperazine melting point 195.1°C. 

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