Sulfuryl amide

Insertion products of SO2 or SO3 and a metal amide are not, in the majority of cases, isolated owing to loss of a thionyl or sulfuryl amide with concomitant formation of a compound having an M=0 or M—O—M bond. This is illustrated for amides of boron ... 

The exothermic reaction which occurs when sulfuryl amide is heated was discovered by Traube (111). 

The ammonium salt which results from the transformation of sulfuryl amide can be converted to a silver salt, AgNSO ELO, by silver nitrate (64) and this readily gives AgNS02. The silver salt with methyl iodide yields the N-methyl derivative (LXXI) (61). Since molecular weight determinations show the methyl derivative to be a trimer, it may also be assumed that the salts, and particularly that of silver, are also trimeric. Attempts to isolate the hydrogen compound (LXIX) have so far failed, but Heinze and Meuwsen (64) have prepared many salts of (LXIX). They also were able to show that when the silver salt was decomposed with an equivalent quantity of hydrochloric acid a tribasic acid resulted which was to some extent stable in water. It readily lost two protons, but one proton was split off only with difficulty. The ion (LXX) clearly has a high stability. The dipyridinium salt of the trimeric sulfimide, which is derived from the ion (LXX), can be obtained (la) in a yield of 70% by reaction of amido-sulfuric acid chloride with pyridine at 20° ... 

It is striking that compound (LXXVa) is clearly much more stable than the isomer (LXXVb) and that hydrolysis leads to different products. Whereas sulfimide in an acid medium gives sulfuryl amide, amidosulfonic acid and sulfuric acid, the hydrolysis of sulfanuric acid leads to imidosulfamide (86). 

Sulfuryl amide (LXXIX), the diamide of sulfuric acid, has been known for a very long time. It was discovered by Traube (111, 112) and isolated as a colorless solid mp, 92-93°. It is formed in a quite normal way both in the ammonolysis of sulfuryl halides (see, for example, refs. 22,26,29, 77,103, 119) and also in the ammonolysis of sulfur trioxide (6). It is common to both modes of preparation that other reactions occur besides the formation... 

According to current views on the formation of sulfuryl amide (6, 44)> a condensation reaction probably leads in each case to the formation of (LXXIX). 

Since, however, both S03 and the ion 02SC1+, which is analogous to sulfur trioxide, are not only capable of undergoing condensation reactions but, as Lewis acids, also have a strong tendency to undergo addition reactions, the formation of sulfuryl amide cannot be the only reaction of these substances with ammonia. 

An interesting and almost quantitative formation of sulfuryl amide is based on the use of sulfuryl diisocyanate (LXXXII), which can be made by the action of cyanogen bromide on sulfur trioxide (60), or by the reaction of chlorosulfonyl isocyanate (LXXXI), with silver cyanate (3). 

Hydrolysis of this substance leads by intermediate steps to sulfamide (Scheme 1). Ammonolysis, on the other hand, yields a cyclic mixed derivative of sulfuric acid and carbonic acid (LXXXIII). Sulfuryl amide gives salts and also numerous organic derivatives. A silver salt (AgNH)2S02... 

Imidodisulfamide (LXXVIII) is formed extraordinarily readily from sulfuryl amide when it is heated for some time with dilute sodium hydroxide solution (75). The resulting sodium salt is decomposed with sulfuric acid and the imidodisulfamide dissolved out with acetone. Like sulfuryl amide, imidodisulfamide is also a colorless solid (inp, 169°) which dissolves in water and in some organic solvents, such as acetone or ethyl acetate. 

When sulfuryl amide or imidodisulfamide is heated with strong sodium hydroxide solution, the sodium salt of amidosulfonic acid results. The free acid itself may be prepared in various ways for example, from urea and sulfuric acid, from many adducts of sulfur trioxide and ammonia, from hydroxylammonium salts and sulfur dioxide, or from SO and acetoxime. Amidosulfonic acid, which is colorless and melts at 205° with decomposition, has, as Baumgarten supposed (13), the structure (LXXXVII). 

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