Ortho-tolyl groups

The mass spectra of aryl methanesulfonates were examined42 with the expectation of observing enhanced intensities for the ions at m/z 80 and m/z 97, if an ortho methyl group were present, e.g. in o-tolyl methanesulfonate (56). However, neither ions were formed but an intense signal at m/z 108 was ascribed to the radical cation of 0-cresol (equation 12), produced by loss of a neutral sulfene molecule. The ion at m/z 108 was the base peak in the mass spectrum of m-tolyl methanesulfonate, showing that the presence of a methyl group in the ortho position was not essential for its formation. The mass spectrum of 56 was... 

The rate of alkaline hydrolysis of 1-ArOAc to form 1-ArOH was monitored at 25 C 0.1 C, and was followed for 10 half lives at A. = 275 nm. 1 x 10" M 1-ArOAc was dissolved in 0.1 M NaOH. The plots of In (A - A) versus time were linear for 3 - 4 half lives with cc > 0.998. The second order rate constant for hydrolysis is 2.8 x 10" M" sec" Reported rates of alkaline hydrolysis for phenyl acetate and / -tolyl acetate are 0.576 and 0.310 M" sec respectfully (29). The rate of alkaline hydrolysis of 1-ArOAc should be slower than that of phenyl acetate and />-tolyl acetate because of the two ortho-methyl groups of 1-ArOAc, are electron-donating and sterically hinder attack of the OH". 

The introduction of an oxygen linker between the two phenyl groups (9k) led to somewhat reduced inhibitory activity. Switching to simple phenyl residues on the 6-amino acid scaffold, the ortho-tolyl derivative 9b showed a noticeable... 

Sulfonation increases the water solubiUty of dyes. A sulfonic group is electron withdrawing but has a weakening effect on the fluorescence only if it is ortho to the donor group. For example, in Brilliant Sulfoflavine FF [2391-30-2] (17), where R = p-tolyl, —it has a weakening effect, although the cleanness of the fluorescent color is somewhat improved compared to that of the unsulfonated compound. 

The condensation of dichloride 57 with the dianion of N-methyl ortho-tolylamide 56 affords pyrrolo[2,3-d]-[2]benzazepin-6(lH)-one 58 (R = p-tolyl). The product 58 contains four rather than just two imino groups. This can be explained... 

In 1969, Elschenbroich and Cais reported the ESR spectra of several ferrocenyl anion radicals, including benzoyl, p-tolyl, p-carbomethoxy-benzoyl, p-nitrophenyl, p-cyanophenyl, and nitroferrocene, prepared by electrolytic reduction in either acetonitrile or DMF (5S). In general, the ferrocenyl group destabilizes the anion radicals compared to a phenyl substituent. When both groups are present, delocalization of the unpaired electron into the phenyl substituent is more extensive, and the ESR spectra resemble, for the most part, anion radicals of substituted aromatics. There is small spin density in the ferrocenyl moiety, which appears as small hyperfine couplings for the cyclopentadienyl protons ortho to the point of substitution (38). 

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