Synthese of sulfonated derivatives of 2‐amino‐p‐xylene Sulfonation of 2‐amino‐p‐xylene (2) gave 2‐amino‐p‐xylene‐5‐sulfonic acid (1). The 2‐amino‐p‐xylene‐6‐sulfonic acid (3) was prepared via three routes: (1) sulfonation of 2‐amino‐5‐chloro‐p‐xylene (19) to 5‐amino‐2‐chloro‐p‐xylene‐3‐sulfonic acid (20) followed by hydrogenolysis; (2) sulfur dioxide treatment of the diazonium salt derived from 2‐amino‐6‐nitro‐p‐xylene (21) to 2‐nitro‐p‐xylene‐6‐sulfonyl chloride (11) followed by hydrolysis to 2‐nitro‐p‐xylene‐6‐sulfonic acid (4) and Béchamp reduction; (3) Béchamp reduction of 2‐chloro‐3‐nitro‐p‐xylene‐5‐sulfonic acid (13) to 3‐amino‐2‐chloro‐p‐xylene‐5‐sulfonic acid (16) and subsequent hydrogenolysis. Catalytic reduction of 13 in aqueous sodium carbonate solution gave mixtures of 3 and 16. 2‐Amino‐p‐xylene‐3‐sulfonic acid (27) was synthesized via two routes: (1) reaction of 19 with sulfamic acid to 2‐amino‐5‐chloro‐p‐xylene‐3‐sulfonic acid (26) followed by hydrogenolysis; (2) sulfur dioxide treatment of the diazonium salt derived from 2‐amino‐3‐nitro‐p‐xylene (28) to 2‐nitro‐p‐xylene‐3‐sulfonyl chloride (12), hydrolysis to 2‐nitro‐p‐xylene‐3‐sulfonic acid (7) and Béchamp reduction.

Syntheses of some Alkyl, Cycloalkyl and AryI2-Aminophenyl Sulfones SummarySyntheses of the alkyl, cycloalkyl and aryl 2-aminophenyl sulfones 10 were achieved by oxidation of the corresponding 2-nitrophenyl sulfides 7 to the 2-nitrophenyl sulfones 9 followed by ethanolic BPchamp-reduction. The sulfides 7 in turn were obtained either by reactions of 2-nitro-thiophenol (8) with the appropriate alkyl and cycloalkyl halides or of 2-chloro-nitrobenzene (5) with the relevant thiols. Condensation of 2-nitrobenzenesulfinic acid (3) with bromoacetic acid in aqueous alkaline solution led -presumably via 2-nitrophenylsulfonylacetic acid (4) -to methyl 2 nitrophenyl sulfone (l), reduction of which gave 2-aminophenyl methyl sulfone (2). Treatment of 2-aminothiophenol (11) with t-butyl alcohol in aqueous sulfuric acid gave 2-aminophenyl t-butyl sulfide (12), which was acetylated to o-t-butylthio-acetanilide (13). Oxidation of the latter to o-t-butylsulfonylacetanilide (14) followed by hydrolysis led to 2-aminophenyl t-butyl sulfone (15). Als Methode zur Herstellung von

Syntheses of Sulfonated Derivatives of 4‐Amino‐1, 3‐dimethylbenzene and 2‐Amino‐1, 3‐dimethylbenzene Direct sulfonation of 4‐amino‐1, 3‐dimethylbenzene (1) and sulfonation of 4‐nitro‐1,3‐dimethylbenzene (4) to 4‐nitro‐1,3‐dimethylbenzene‐6‐sulfonic acid (3) followed by reduction yield 4‐amino‐1,3‐dimethylbenzene‐6‐sulfonic acid (2). The isomeric 5‐sulfonic acid (5) however is prepared solely by baking the acid sulfate salt of 1. Reaction of sulfur dioxide with the diazonium chloride derived from 2‐amino‐4‐nitro‐1,3‐dimethylbenzene (7) leads to 4‐nitro‐1,3‐dimethylbenzene‐2‐sulfonyl chloride (8), which is successively hydrolyzed to 4‐nitro‐1,3‐dimethylbenzene‐2‐sulfonic acid (9) and reduced to 4‐amino‐1, 3‐dimethylbenzene‐2‐sulfonic acid (6). Treatment of 4‐amino‐6‐bromo‐1,3‐dimethylbenzene (12) and 4‐amino‐6‐chloro‐1, 3‐dimethylbenzene (13), the former obtained by reduction of 4‐chloro‐6‐nitro‐1,3‐dimethyl‐benzene (10) and the latter from 4‐chloro‐6‐nitro‐1, 3‐dimethylbenzene (11), with oleum yield 4‐amino‐6‐bromo‐1,3‐dimethylbenzene‐2‐sulfonic acid (14) and 4‐amino‐6‐chloro‐1,3‐dimethylbenzene‐2‐sulfonic acid (15) respectively; subsequent carbon‐halogen hydrogenolyses of 14 and 15 lead also to 6 (Scheme 1). Baking the acid sulfate salt of 2‐amino‐1, 3‐dimethylbenzene (17) gives 2‐amino‐1, 3‐dimethylbenzene‐5‐sulfonic acid (16), whereas the isomeric 4‐sulfonic acid (18) can be prepared by either of the following three possible pathways: Sulfonation of 2‐nitro‐1,3‐dimethylbenzene (20) to 2‐nitro‐1,3‐dimethylbenzene‐4‐sulfonic acid (21) followed by reduction or sulfonation of 2‐acetylamino‐1,3‐dimethylbenzene (19) to 2‐acetylamino‐1,3‐dimethylbenzene‐4‐sulfonic acid (22) with subsequent hydrolysis or direct sulfonation of 17. Further sulfonation of 18 yields 2‐amino 1,3‐dimethylbenzene‐4,6‐disulfonic acid (23), the structure of which is independently confirmed by reduction of unequivocally prepared 2‐nitro‐ 1,:3‐dimethylbenzene‐4,6‐disulfonic acid (24)(Scheme 2).

Some comments on the syntheses of 5-amino-rn-xylene-2-sulfonic acid and 5-amino-m-xylene-4-sulfonic acid SummaryTreatment of 5-amino-m-xylene (1) with oleum led to a 55:45 mixture of 5-amino-m-xylene-2-sulfonic acid (2) and 5-amino-m-xylene-4-sulfonic acid (3). The structure of both isomers was proven by reaction of sulfur dioxide with the diazonium chlorides derived from 2-amino-5-nitro-rn-xylene (5) and 4-amino-5-nitrom-xylene (8) giving 5-nitro-m-xylene-2-sulfonyl chloride (6) and 5 -nitro-m-xylene-4-sulfonyl chloride (9) respectively, followed by hydrolyses to the corresponding sulfonic acids 7 and 10, and final Bkchamp reductions. The sulfonic acid 2 was also prepared by sulfonation of 5-acetylamino-m-xylene (4) to 5-acetylamino-m-xylene-2-sulfonic acid (11) and subsequent hydrolysis. A further procedure for the synthesis of 3 was sulfonation of 5-amino-2-chloro-m-xylene (12) -prepared by Bdchamp reduction of 2-chloro-5-nitro-m-xylene (13) -or of 5-amino-2-bromo-mxylene (15) -prepared by bromination of 4 and subsequent hydrolysis -to 5-amino-2-chloro-m-xylene-4-sulfonic acid (16) and 5-amino-2-bromo-m-xylene-4-sulfonic acid (17) respectively, followed by hydrogenolysis.Synthesen der beiden von 5-Amino-m-xylol (1) herleitbaren Sulfonsauren, 5-Amino-m-xylol-2-sulfonsaure (2) und 5-Amino-m-xylol-4-sulfonsaure (3), sind nicht bekannt. Einzig fur 5-Acetylamino-m-xylol (4) ist die Reaktion mit Chlorsulfonsaure zu 5-Acetylamino-m-xylol-2-sulfonylchlorid beschrieben [ 11.Bei der Reaktion von 1 mit Oleum wurde gemass Dunnschichtchromatogramm vollstandige Umsetzung unter Bildung zweier sulfonierter Produkte beobachtet. Das NMR.-Spektrum') des isolierten Gemisches in einer Losung von deuteriertem Natriumhydroxid in Deuteriumoxid zeigte bei 6,61 ppm ein einziges Signal fur aromatische Protonen, sowie ein Signal bei 4,78 ppm fur austauschbare Protonen und zwei Signale fur Methylprotonen bei 2,57 ppm und 2,20 ppm. Unter der sich spater bestatigenden Annahme, dass ein Gemisch der Sauren 2 und 3 vorlag, musste das Signal bei 2,57 ppm den Protonen der in o-Stellung zu einer Sulfonsauregruppierung stehenden Methylgruppen und das Signal bei 2,20 ppm den Protonen der sich in I) Die chemischen Verschiebungen 6 sind in ppm angegeben; vgl. exper. Teil.

Symmetrische Flavylocyanine bilden sich bei der Kondensation von 2 Mol Flavyliumperchlorat mit Malonsäure und deren Vinylenhomologen unter selbsttätiger Dehydrierung und Decarbonylierung.