Search

p-Benzoquinone ( 1) reacts with dialkylamines 2a-d to 2-dialkylamino- p-benzoquinones 3, 2,5- bis-dialkylamino- p-benzoquinones 4, 2-dialkylamino-8-hydroxydibenzofuran-1,4-quinones 5, and in pyridine also to 2-dialkylamino-5- p-hydroxy-phenoxy- p-benzoquinones 6. A method affording almost exclusively 3 has been developed which is also applicable to compounds 2e-h. [ABSTRACT FROM AUTHOR]

Acetylation of the indazolquinones 1a (6-anilino-), b (6- p-toluidino-), c (6-N-methylanilino-), g (6- or 5-methylthio-), and k (benz[f]-) by heating with acetic anhydride yields the 2-acetylindazolquinones 4a, b, c, g, and k. Reductive acetylation of the quinones 1c, g, h/h(6/5-methyl), k and - for structure elucidation - their 1-N- ( 2c) and 2-N- ( 3c, 3e)-methyl derivatives with acetic anhydride, zink powder, and sodium acetate gives the 1-acetyl-( 7c, g, h/h, k), resp. 1-methyl- ( 8c), and 2-methyl- ( 9c, e) diacetoxyindazoles. In case of 1k, two diacetyl derivatives were isolated in addition to the already known triacetyl derivative 7k, regardless of the conditions chosen. Acetylation of the intermediate product of the reaction from phenylthio-benzoquinone with diazomethane also yields a triacetyl-hydroquinone ( 7f). UV/Vis, IR, andH NMR spectroscopy were used for structure determination. Comparison of the UV/Vis spectra of the acetyl derivatives 4 with those of 1, 2, 3, and of compounds 7 with those of analog substituted indazols shows that the acetyl group is located in position 2 with compounds 4 and in position 1 with compounds 7. By means ofH NMR spectra the position of the acetyl group can be determined by the effect of the carbonyl group on the proton in position 3. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Monthly / Monatshefte für Chemie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)