Sulfonic acids from sulfonation with rearrangement

Rearrangement appears to be a property of the sulfonic acids themselves and not of the hydrocarbons, since durenesulfonic acid rearranges in contact with phosphorus pent oxide, but durene itself will not.55 Similarly, the sulfonic acid from pentamethylbenzene will rearrange in a desiccator over sulfuric acid, whereas the hydrocarbon will not.54... 

Typical primary amines which undergo such nitrosation are m-toluidine, p-xylidine, m-anisidine, 2-amino-4-methoxytoluene, 3-amino-4-methoxy-toluene, m-aminophenol, a-naphthylamine, l-naphthylamine-2-, -6-, -7-, and -8-monosulfonic acids, and l-naphthylamine-4-monosulfonic acid (which reacts with displacement of the sulfonic acid group). The secondary amines derived from these primary amines also can be nitrosated directly (i.e., without the intermediate formation of an JV-nitroso compound which needs to be subjected to the Fischer-Hepp rearrangement). The entering nitroso group appears to substitute exclusively in the para position. 

The reaction of 2-acetyl-3-hydroxypyridine (441) with hydroxylamine 0-sulfonic acid afforded a 1 1 mixture of compound (442) and 2-methylisoxazolo[4,5-6]pyridine (443) (Equation (35)) <87H(26)292i). The formation of the oxazolo[4,5-6]pyridine (442) results from a Beckmann rearrangement. The reaction of the oxime (444) with hydroxylamine O-sulfonic acid also gave Beckmann rearrangement products, such as (445) and (446) as a 1 1 mixture (Equation (36)). 

The above method of sulfonation with sulfurous acid finds further application in the preparation of p-aminophenoldisulfonic acad from nitrosodimethylaniline and sodium bisulfite. In the rearrangement to the disulfom c acad, the dimethylamino group is split off with the formation of the p-aminophenol derivative. Pure dimethyl-amine is formed in the reaction. 

Sodium hydroxide Elimination of sulfur dioxide from sulfonic acid amides with rearrangement... 

Sulfation by sulfamic acid has been used ia the preparation of detergents from dodecyl, oleyl, and other higher alcohols. It is also used ia sulfating phenols and phenol—ethylene oxide condensation products. Secondary alcohols react ia the presence of an amide catalyst, eg, acetamide or urea (24). Pyridine has also been used. Tertiary alcohols do not react. Reactions with phenols yield phenyl ammonium sulfates. These reactions iaclude those of naphthols, cresol, anisole, anethole, pyrocatechol, and hydroquinone. Ammonium aryl sulfates are formed as iatermediates and sulfonates are formed by subsequent rearrangement (25,26). 

Selective hydroxylation with osmium tetroxide (one equivalent in ether-pyridine at 0 ) converts (27) to a solid mixture of stereoisomeric diols (28a) which can be converted to the corresponding secondary monotoluene-sulfonate (28b) by treatment with /7-toluenesulfonyl chloride in methylene dichloride-pyridine and then by pinacol rearrangement in tetrahydrofuran-lithium perchlorate -calcium carbonate into the unconjugated cyclohepte-none (29) in 41-48 % over-all yield from (27). Mild acid-catalyzed hydrolysis of the ketal-ketone (29) removes the ketal more drastic conditions by heating at 100° in 2 hydrochloric acid for 24 hr gives the conjugated diketone (30). 

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