Butyl chloride pyrolysis

This study on the kinetic chlorine isotope effect in ethyl chloride50 was extended to secondary and tertiary alkyl halides pyrolyses51. The isotope effects on isopropyl chloride and terf-butyl chloride pyrolysis were found to be primary and exhibited a definite dependence on temperature. They increased with increasing methyl substitution on the central carbon atom. The pyrolysis results and model calculations implied that all alkyl chlorides involve the same type of activated complex. The C—Cl bond is not completely broken in the activated complex, yet the chlorine participation involves a combination of bending and stretching modes. 

Finally, Markl has developed two novel arsabenzene syntheses, which involve carbenoid ring expansion from arsacyclopentadienes. l-t-Butyl-2,5-diphenylarsole 38 adds dichlorocarbene to give 39, which on pyrolysis loses t-butyl chloride to afford 3-chloro-2,6-diphenylarsabenzene 40 40). 

The proposed transition states have been supported by deuterium isotope studies Evidence such as the decomposition behaviour in solution and the nature of the increases in the rates of decomposition along the series of chloro-formates methyl, ethyl, isopropyl, 2-butyl, /-butyl suggests that the transition states are somewhat polar °> . Lewis and Herndon found 2-methylbut-1-ene and 2-methylbut-2-ene as the olefinic products of the elimination reaction of neopentyl chloroformate, and the kinetic evidence supports a Wagner-Meerwein rearrangement in the gas-phase as in the case of neopentyl chloride pyrolysis (refs. 407, 408, 566). 

No examples of catalysis of unimolecular elimination from halides or esters have been reported. Fades and Stimson (1962) have shown that t-butyl chloride undergoes elimination in the gas-phase at a rate independent of the partial pressure of added sulphur hexafluoride, a substance known to accelerate certain decompositions (Bose and Hinshelwood, 1959). However, the pyrolysis of alcohols, first studied by Kistiakowsky and Schultz (1934) is accelerated by the presence of hydrogen halides (Maccoll and Stimson, 1960). The former authors showed that t-butyl alcohol decomposed homogeneously to yield isobutene and water, at a rate given by... 

Products and characteristics of plasma pyrolysis Dichloroethane, rate 8 kg/h Butyl chloride, rate 5.4 kg/h Hexachlorane Organic chlorine mixture, rate 7.2 kg/h... 

Thermal Plasma Pyrolysis of Dichloroethane, Butyl Chloride, Hexachlorane, and Other Organic Chlorine Compounds for Further Synthesis of Vinyl Chloride... 

Though the PECH decomposes to indefinite fragments with n-butyl lithium or sodium hydride in THF at room temperature, it reacts with sodium methoxide with liberation of Cl in which the -elimination of hydrogen chloride predominates instead of nucleophilic substitution. For instance, PECH in DMSO was reacted with double the molar quantity of sodium methoxide at room temperature for 24 h to give the unsaturated polyether (DS 92.3%,v(C=C) 1630,5 (=CH2) 795 cm" ) after purification by dissolution(DMF)-precipitation (H20) technique. A similar unsaturated polyther was obtained by the pyrolysis of the sulfilimine 13 (110-130°C) but not of sulfoxide 12 (100-150°C). When the polymer 26, was heated to 90°C, the absorption of C=C and =CH2 decreased and a new absorption at 1720 cm appeared and increased. This is explained as a result of [3.3] sigmatropic rearrangement of to afford including C=CH2 and C=0 structure as shown in equation 7. 

Chemical/Physical. Pyrolysis of di-n-butyl phthalate in the presence of polyvinyl chloride at 600 °C gave the following compounds indene, methylindene, naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, biphenyl, dimethylnaphthalene, acenaphthene, fluorene, methylace-naphthene, methylfluorene, and six unidentified compounds (Bove and Dalven, 1984). 

Addition of aryl tellurium trihalides to cyclohexene produces trails-] -aryldihalotelluro-2-halocyclohexanes when the reactions are carried out in chloroform, and trans-1-aryldihalotelluro-2-methoxycyclohexanes when methanol is used as the reaction medium. Treatment of the 2-chlorocyclohexyl 4-methoxyphenyl tellurium dichloride with terf.-butyl hydroperoxide in acetic acid yielded tram-l,2-dichlorocyclohexane and aryl chloride. Bis[4-methoxyphenyl] tellurium dichloride did not yield any aryl chloride under these conditions1. Pyrolysis of tran.s-2-methoxycydohexyl phenyl tellurium dibromidc afforded Crum- l-bromo-2-methoxycyclohexane1. 

The pyrolysis of r-butyl peroxy esters in suitable hydrogen donor solvents has been reviewed by Rtichardt. Ihe method involves the reaction of an acyl chloride widi r-butyl hydroperoxide followed by thermolysis of die resulting pooxy ester in cumene or p-cymene. Yields are moderate, but the pyrolysis step tolerates a certain degree of functionality as Ulustrated in equation (8). More recendy, the use of ethyl phenylacetate as die pyrolysis solvent and hydrogen donor has been advocated. 

The liquid ammonia was then driven off, an equivalent of the ketone was added, and the mixture refluxed for completion of the aldolization. Lithium amide proved to be superior to sodium amide for these condensations. /-Butyl esters were preferred because they are readily cleaved by pyrolysis or by acid. Dehydration to the a,fi-unsaturated esters could be effected with thionyl chloride and pyridine. Hauser and Lindsay succeeded in effecting aldol condensation with ethyl acetate, which undergoes self-condensation very readily two equivalents of base were used. Sisido has reported further alkylations of /-butyl esters. 

Aliphatic thioacyl chlorides, e.g. Bu CH2C(S)Cl and Bu CHClC(S)Cl, can be obtained by addition of hydrogen chloride or chlorine, respectively, to the thioketen Bu CH=C=S, generated by flash pyrolysis of 4-t-butyl-l,2,3-thiadi-azoles or by direct reaction with the heated thiadiazole. The addition of hydrogen chloride to the alkynethiolate ion Bu C=CS also gives the thioacyl chloride Bu CHaC(S)Cl. Addition of thiophosgene to the enamine Mc2NC(Bu )=CHa... 

---