ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Syntheses of Sulfonated Derivatives of 4-Amino-1, 3-dimethylbenzene and 2-Amino-1, 3-dimethylbenzeneDirect 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).
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19780610834
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