Zur Synthese und Struktur der p-Indazolchinone und ihrer Methylierungsprodukte Untersuchungen ueber Chinone, 8. Mitt.

Article abstract of DOI:10.1007/BF00812321

The p-benzoquinones 5e-j react with diazomethane (after dehydrogenation) to 6-anilino- 2e, dimethylamino- 2h, phenylthio- 2i, and methylthioindazolquinone 2j.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) 2 l, n, and benz-indazolquinone 2o yield the 1- and 2-N-methyl derivatives 3 and 4.The structure of the 2-methyl derivatives is established by reaction of the corresponding benzoquinones with 3-methylsydnon in the case of 4e, 4g.UV/VIS-, IR- and 1H-NMR-spectroscopy (in CDCl3 and DMSO) were used for structure determination.Comparison of the UV/VIS-spectra of 2-4 shows that the indazolquinones are existing as 2 H-4,7-diones.For the structure elucidation of the l-rs. 2-methylderivatives (which 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.Keywords. p-Indazolquinones