Synthesis tetrachloromethane

These results may be viewed in the wider context of interactions between potential ligands of multifunctional xenobiotics and metal cations in aquatic environments and the subtle effects of the oxidation level of cations such as Fe. The Fe status of a bacterial culture has an important influence on synthesis of the redox systems of the cell since many of the electron transport proteins contain Fe. This is not generally evaluated systematically, although the degradation of tetrachloromethane by a strain of Pseudomonas sp. under denitrifying conditions clearly illustrated the adverse effect of Fe on the biotransformation of the substrate (Lewis and Crawford 1993 Tatara et al. 1993). This possibility should therefore be taken into account in the application of such organisms to bioremediation programs. 

A convergent synthesis of chiral 6,5-bicyclic hexahydropyridazine derivative 394 is described. Methyl ester 391 is deprotected with perchloric acid in aqueous THF to provide the corresponding diol 392. Its cyclization is achieved by refluxing its dichloromethane solution with excess triphenylphosphine, tetrachloromethane, and triethylamine. The crude hydroxy derivative 394 is separated from triphenylphosphineoxide via the corresponding silylated derivative 393 (Scheme 60) <1995H(41)2487>. 

Isomerically pure chlorofullerene C oClg has been reported to be the predominant product of the reaction of with an excess of iodine monochloride in benzene or toluene at room temperature (Scheme 9.11) [79], The product is very soluble in benzene, carbon disulfide and tetrachloromethane. Deep orange crystals can be obtained by recrystallization from pentane. The synthesis of CjoClg using toluene as a solvent proceeds more slowly than with benzene, indicating that radicals are involved and are scavenged by the toluene [79],... 

Dichlorourethane and tert-butyl hypochlorite (TBH) were even more reactive in the presence of silica, chlorination of toluene with TBH being complete in just one hour at ambient temperature with 3.8g of BDH silica for a 5 mmol reaction in 10 ml of tetrachloromethane solvent Intrigued by these observations, we decided to undertake a more systematic investigation of the potential of solid catalysts for organic synthesis. 

Halides are often prepared in a single step from alcohols through use of the Appel reaction. The reagents in this synthesis are tri-phenylphasphine and a halogen species such as tetrachloromethane, hexachloroacetone, or iodine. In place of the Appel reaction it is often possible to use inorganic acid chlorides, including phosphorus tribromide or thionyl chloride (see Chapter 16). 

Murray, W.T., Kelly, J.W., and Evans, S.A., Jr., Synthesis of substituted 1,4-oxathianes mechanistic details of diethoxytriphenyl phosphorane and triphenylphosphine/tetrachloromethane — promoted cyclodehydrations and 13C NMR spectroscopy, J. Org. Chem., 52, 525, 1987. 

The preparation of monochloroborane in ether is capricious and the product is not stable. A more convenient source of monochloroborane is its dimethyl sulfide complex, which is readily prepared by reaction of borane-dimethyl sulfide with either tetrachloromethane (equation 22) or trichloroborane-dimethyl sulfide (equation 23). The latter reaction has also been modified for synthesis of the bromoborane and iodoborane complexes. 

Lakhrissi, M, Chapleur, Y, Dichloromethylenation of lactones 6 efficient synthesis of dichloroolefins from lactones and acetates using triphenylphosphine and tetrachloromethane, J. Org. Chem., 59, 5752-5755, 1994. 

The reactions of tetrachloromethane with sulfur(VI) oxide have been discussed in Section 5.2.1.1. Phosgene has been detected in the synthesis of TeCl from TeOj and CCl, [1103a]. 

The a-chlorophosphonates are valuable intermediates that have applications in the synthesis of alkynes, chloroolefins, and 1,2-epoxyphosphonates. Tetrachloromethane seems to be the most widely used reagent in the electrophilic monochlorination of phosphonates, presumably because it gives very clean chlorine transfer and produces an easily removed byproduct (chloroform) (Scheme 3.27). Only leq of base (n-BuLi) is needed to achieve the two successive deprotonations. A large number of chloroalkenes, some of them showing interesting insecticidal properties, have been obtained in 27-87% yields by this method (Scheme 3.27). ... 

Synthesis from sucrose 1-Deoxymannojirimycin (2) was synthesized from sucrose by treatment with triphenylphosphine and tetrachloromethane followed by Sn2 displacement of the resulting chloride groups with azide ion to afford the 6,6 -diazido-6,6 -dideoxysucrose 65 in 57% overall yield from sucrose (Scheme 13). Hydrolysis of 65 with ion-exchange resin afforded a mixture of 6-azido-6-deoxy-D-glucose (66) and 6-azido-6-deoxy-D-fructofuranose (67). The azido derivative 66 was converted into 67 in 25% yield... 

Fig. 5 Synthesis of C10-C12 polychloroalkanes (Cle-Clio) via addition of tetrachloromethane, chlorine or hydrogen to double bonds [6]...

Cleophax et al. [35] performed a microwave-assisted synthesis of dichlorovinyl glycopyranosides 47 from per-O-acetylated glycopyranoses 46 via Wittig-type reaction with triphenylphosphine-tetrachloromethane either in toluene and pyridine or dichloromethane on the anomeric acetate group (Scheme 12.22). 

According to the Sagami synthesis, prenol is reacted with methyl orthoacetate. A Claisen rearrangement yields methyl 3,3-dimethylpent-4-enoate, which undergoes a radical addition to tetrachloromethane. The double elimination of hydrogen chloride gives finally permethric acid. In this transformation, the base and the solvent have a critical impact on the cis/trans-ratio. Under the most favourable conditions (t-BuONa, hexane, HMPT) the cis-proportion can reach up to 90%. [102-104]... 

Taylor has demonstrated that conversion of the title sulfoxide, prepared by oxidation of the known sulfide, shown in Scheme 4.67 [124], into two desired enones which were required as starting materials for the synthesis of thiathromboxane analogues, could be carried out using trimethylsilyl chloride (TMSCl) in refluxing tetrachloromethane. At the time, this was the first occasion on which TMSCl had been used in order to effect a Pummerer rearrangement for such species (Scheme 4.67) [125a,b]. 

FIGURE 8.29 UV-Vis-NIR spectra of PPy-DBSA films cast from the solutions in (a) chloroform, (b) chlorobenzene, and (c) tetrachloromethane containing extra DBSA which is removed by washing after evaporation of the solvent. (From Song, K.T., Synthesis of electrically conducting soluble polypyrrole and its characterization. Ph.D. thesis, 2000. With permission.)... 

This nitrile synthesis can be applied equally well to aliphatic and aromatic carboxamides. It is also applicable to the production of 7-chloro-3-cyano-2,3-dihydro-l-methyl-2-oxo-5-phenyl-li-f-l,4-benzodiazepine 1451, which is not accessible using the usual strongly acidic dehydrating agents [1100]. 1451 is produced as an intermediate in a synthesis of imidazo[5,l-c]benzodiazepine-l,4 1452 by dehydration of the carbaldoxime 1450 with triphenylphosphine/tetrachloromethane in 76% yield [1102]. 

Appel s dehydration reagent can be successfully applied to the synthesis of isocyanides 1515 from formamides 1513 [987, 1224]. The dehydration reaction with triphenylphosphine/tetrachloromethane proceeds smoothly and furnishes generally good yields of 89-91% for alkyl, ben2ylic, and aryl isocyanides 1515 [1224]. 

A total synthesis of the natural product ( )-8,15-diisocyano-ll(20)-amphilectme 1653 has been accomplished. In the last step, the two isocyano functions were formed from the corresponding formamides by dehydration with tiiphenylphos-phine/tetrachloromethane [1227]. 

Polymeric reagents bearing an isocyanide group 1654 cannot be prepared easily. A patent application New functionalized polymeric reagents with an isonitrile moiety for solution and solid-phase synthesis details syntheses of such isocyanides 1654 from the corresponding formamides according to an Appel reaction with tiiphenylphos-phane/tetrachloromethane and triethylamine [1228]. 

The industrial synthesis of dichloromethane by thermal chlorination also leads to trichloromethane and tetrachloromethane. An optimal yield of this product is obtained by a large excess of methane and/or methyl chloride relative to chlorine. 

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