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.

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(1) (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(1), 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 triacetylhydroquinone (7f). UV/Vis, IR, and (1)HNMR 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 of (1)HNMR spectra the position of the acetyl group can be determined by the effect of the carbonyl group on the proton in position 3.

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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.

The reaction of N-alkyl-p-hydroxyanilinobenzoquinones1 a–d, its acetylderivatives11–c1 and the methoxyderivative1 a2 with diazomethan yields in dependence on the reaction-conditions the indazolquinones2 a–d, 2 a1–c1 or2a2, the1-methylindazolquinones3 a–d and31–c1, and finally the methoxy-1-methylindazolquinones5 a–d. The 2-methyl-isomeres6 a–d are formed only in small amounts. Methylation of2 a with dimethylsulfate gives5 a and6 a in the ratio of appr 2 to 1. Acetylation of2 a–d with acetanhydride leads to the N−O-acetylderivatives, which are easily hydrolyzed to2 a1–d1 during work up;3 a d yields3 a1–d1. The structures are established by the described crossexperiments and by spectroscopy (UV/VIS, IR, NMR).

In acetic (aqueous or chloroform) solutionp-benzoquinones yield with primary aliphatic amines mainly 2-(N-alkyl-p-hydroxy-anilino)-1,4-benzoquinones besides the 2-alkylamino- and 2,5-bis(alkylamino)-quinones. The methyl-, ethyl-,n-propyl-,n-butylhomologues ofp-benzoquinone and the isomer methylderivatives of toluquinone are described. Their structure were established by spectroscopic (UV/VIS, IR, NMR) methods and by synthesis of the methylderivative3 a fromp-benzoquinone andp-hydroxy-N-methylaniline. The influence of other acids on the reaction was studied.

AbstractDie Umsetzung von Benzochinon (Ia) mit prim. Aminen (II) in Gegenwart von Eisessig führt zur Bildung der N‐Alkylhydroxyanilinobenzochinone (IIIa).

AbstractDas Benzochinon (I) reagiert mit den Aminen (II) zu den Carbazolchinonen (III).

The compound which is obtained in the reaction of 1,4-benzoquinone with methylamine in chloroform was supposed to be 2-methylaminobenzoquinone; actually it is 6-hydroxy-9-methyl-3-methylamino-1,4-carbazolquinone. The structure is proved by spectroscopic methods, through derivates, zinc dust distillation and via synthesis from 2,5,2′,5′-biphenyl-diquinone. A second main product, 2,5-bis(methylamino)quinone, is obtained; varying the reaction conditions shows especially the influence of the solvent. One of the intermediate products is the true 2-methylamino-1,4-quinone. Other substituted 9-alkyl-3-alkylamino-6-hydroxy-1,4-carbazolquinones can be prepared by reaction with the corresponding primary amines.

Dihydro-3-thioxo-3H-1,2-dithiolo[4,3-d]pyrimidin-5(4H)-one (2) geben bei Methylierung 4-Methylderivate (2) bzw. Tetrahydro-3-methylthio-5-oxodithiolopyrimidiniumsalze (6); aus den Dithionen (3) entstehen 5-Methylthio-bzw.5-Methylthio-4-methylderivate (4) bzw. Tetrahydro-3-methylthio-5-thioxodithiolopyrimidiniumsalze (6). Peressigsäure führt2 in das Tetrahydrodithiolopyrimidiniumhydrogensulfat (10) über.2 bzw.3 geben mit Phenylhydrazin 3-Phenylhydrazone; Tetrahydro-3-methylthiodithiolopyrimidiniumjodide (6) reagieren mit Aminen bei Anwesenheit vonHMPT zu den 3-Iminoverbindungen.10 gibt mit Methylketonen und Wasserstoffakzeptoren 3-Acylmethylendihydrodithiolopyrimidin-5(4H)-one.

AbstractDie Heterocyclen (I) werden durch Dimethylsulfat (II) zu den 4‐Methyl‐Derivaten (III) methyliert; mit Methyljodid entstehen aus (I) bzw. (II) die Salze (I Das Dithion (V) reagiert mit (II) zur Methylmercaptoverbindung (VIa); mit überschüssigem (II) wird das Derivat (VIb) gebildet.