Directive effects in the sulfonation of toluene ; Synthesis and attempted rearrangement of some anilinoketones ; The kinetics and mechanism of the addition of bromine to cyclohexene in dichloromethane. solution
The pure sodium salts of the toluenesulfonic acids were prepared by one of two ways. Both methods started with diazotization of the toluidine. In the first method, the diazonium solution was treated with sulfur dioxide and copper powder, and the resulting sulfinic acid was oxidized to the sulfonic a...
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| Format: | Others |
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BYU ScholarsArchive
1963
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| Online Access: | https://scholarsarchive.byu.edu/etd/8202 https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9202&context=etd |
| Summary: | The pure sodium salts of the toluenesulfonic acids were prepared by one of two ways. Both methods started with diazotization of the toluidine. In the first method, the diazonium solution was treated with sulfur dioxide and copper powder, and the resulting sulfinic acid was oxidized to the sulfonic acid with potassium permanganate. In the second method, the diazonium solution was treated with cuprous chloride and sulfur dioxide to give the sulfonyl chloride which was hydrolyzed to the sulfonate. Toluene was sulfonated by SO3 (enriched with S-35) in refluxing SO2 solution. The isotope dilution technique was used to determine the isomer distribution as 5.6 ± 0.6% ortho, 9.7 ± 0.4% meta, and 84.8 ± 1% para. A mixture of benzene and toluene was sulfonated as before, and the isotope dilution technique was employed to give the rate of sulfonation of toluene relative to that of benzene as 25 ± 7. This value with the isomer distribution gave partial rate factors in the sulfonation of toluene as of 4.2, mf 7.3, and pf 127. Some a-anilinoketones were prepared starting with the appropriately substituted benzaldehydes. The benzaldehyde was condensed with nitroethane to give a 1-phenyl-2-nitropropene, which was treated with acid and iron powder to give the phenylacetone. The phenylacetone was brominated in acetic acid and the resulting a-bromophenylacetone was treated with the appropriately substituted aniline to give the a-anilinophenylacetone. The anilinoketones prepared in this manner were 1-(4-chloroanilino)-1-(4-chlorophenyl)-2-propanone, its dibromo analog, and 1-(3-chloroanilino)-1-(3-chloropbenyl)-2-propanone. These anilinoketones were subjected to rearrangement conditions: refluxing ethanol, refluxing ethylene glycol, ethylene glycol heated at 105° by a refluxing toluene bath, or ethylene glycol heated at 150° by a refluxing bromobenzene bath, with γ-picoline hydrobromide as catalyst. No rearrangement was detected (ultraviolet analysis) in any of the conditions used in this work. The kinetics of the addition of bromine to cyclohexene in dichloromethane solution was studied at 0° and -22.9° using vacuum line techniques. The product was shown to be trans-1, 2-dibromocyclohexane by comparison of physical constants found with those in the literature and by use of a gas chromatograph. The order of the reaction as determined by the differential method was found to be 1.7 at 0° and 1.4 at -22.9°. The rate constants were calculated to be 80 ± 16 liter 0.7/mole 0.7 sec. at 0° and 48 ± 9 liter 0.4/mole 0.4 sec. at -22.9°. These results indicate a complex system with competing reactions. A possible mechanism is suggested as a explanation for the results. |
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