Zur Synthese und Struktur derp-Indazolchinone und ihrer Methylierungsprodukte Untersuchungen über Chinone, 8. Mitt.

Summary Thep-benzoquinones5e-j react with diazomethane (after dehydrogenation) to 6-anilino-2e, dimethylamino-2h, phenylthio-2i, and methylthioindazolquinone2j. Methylation with dimethylsulfate of these as well as of the already known indazolquinones 6-toluidino-2f, 6-methylanilino-2g, 5-tert.butyl-2m, 5,6-methyl- (isomer mixture)2l,n, and benz-indazolquinone2o yield the 1-and 2-N-methyl derivatives3 and4. The structure of the 2-methyl derivatives is established by reaction of the corresponding benzoquinones with 3-methylsydnon in the case of4e,4g. UV/VIS-, IR- and¹H-NMR-spectroscopy (in CDCl₃ andDMSO) were used for structure determination. Comparison of the UV/VIS-spectra of2–4 shows that the indazolquinones are existing as 2 H-4,7-diones. For the structure elucidation of the 1- rs. 2-methylderivatives (whichh can be attributed to the methylation products) NMR-spectroscopy is well suited even without knowing the second isomer (solvent-effect). The course of the reaction of quinones with diazomethane and of the methylation reactions of the indazolquinones is discussed.

Herrn Univ.-Prof. Dr. G. Zigeuner zum 70. Geburtstag gewidmet