2-Amino-5-sulfamic acid

For compound 22, X-ray analysis demonstrates that the dioxane ring adopts the chair conformation and that the imidoyl amino group prefers an axial conformation <2002T2621>. For (l,4-benzodioxin-2(3//)-yl)methyl sulfamic acid ester 21, the conformation of the dihydrodioxin ring is close to an ideal half-chair and for 1,2,4,6,7,9-hexafluoro-... 

Structurally related to a-amino aeids is sulfamic acid, which can exist as neutral (H2N—SO3H) and zwitterionic species (+H3N—S03 ). According to high level ab initio MO calculations, the neutral form is slightly more stable in the gas phase (by ca. 2 kJ/mol), whereas in polar media the zwitterion is predicted to be strongly favoured, in agreement with measurements in aqueous and DMSO solution [261]. 

Meyer and Schwartz, in a study of model compounds structurally related to heparin, showed that the hydrolytic release of sulfate under acid conditions from 2-amino-2-deoxy-D-glucose A -sulfate is more rapid than from D-glucose 6-0-sulfate. These workers also obtained a biologically inactive, nitroso derivative of heparin, and offered this as evidence for a sulfamic acid linkage in the molecule. Wolfrom, Shen and Summers prepared methyl 2-amino-2-deoxy-A-sulfo-tri-0-sulfo-(3-D-glucopyranoside dibarium salt, and found that, on heating a 3 X 10 M solution in 0.004 N hydrochloric acid, the A-sulfate is lost in 20 minutes and the 0-sulfate after 12 hours. 

Berglund showed that sulfamic acid derivatives are relatively stable under alkaline conditions which cause hydrolysis of A-acetamido groups. Jorpes, Bostrom and Mannson, utilizing these data, found that less than 10% of the total amino groups is liberated when a 0.2% solution of heparin in N sodium hydroxide is heated at 100° for 2 hours, whereas 55 % of that in chondroitinsulfate is released. 

It is. significant in that it gives not only amines but also o- and p-amino sulfonic acids, all in one reaction. It is generally carried out with excess sodium bisulfite (4.5-6.0 moles per mole of nitro compound), usually with the addition of enough caustic soda to form the required amount of neutral sulfite. A solvent, such as ethyl alcohol or pyridine, often helps to speed up the reaction, particularly for nitro compounds that are either difficultly soluble or wettable. It is interesting to note that sulfamic acids have also been isolated from this reaction in certain cases. Examples of nitro compounds that may be reduced by the Piria method are p-nitrotoluene, which forms p-toluidine in about 70 per cent yield p-nitrobenzoic acid, which forms 4-amino-3-sulfobenzoic acid and 4-nitronaphthalic anhydride, which forms 4-amino-3-sulfonaphthalic anhydride. 

The 8-amino-7-nitrosopyrimido[2,l-fe][l,3]thiazine (352 R = Me, OH) was reduced to the diamino derivative (398) with Pd/C, H2, or sodium hydrosulfite. In the latter reaction, the sulfamic acid (350 R = Me, OH) and the thiadiazolo derivative (399) were also obtained as by-products... 

Triohloro[(triohlorophosphoranylidene)amino]phosphorus(V) hexaohlorophosphate, synthesis 23 Imidodisulfuric acid chloride, synthesis 26 Dialkylsulfamoyl chlorides, synthesis 27 Dialkylamides of (trichlorophosphoranylidene)sulfamic acid, synthesis 29... 

Several experimental studies have examined sulfamic acid (H3NSO3) which exists predominantly in its zwitterion form in its crystals and in its neutral form in aqueous solution, and is described as the simplest amino sulfonic acid [430] ... 

Oxidation of furfural with chlorine water or sodium hypochlorite followed by treatment of the product (see Section I.l.C,) with sulfamic acid gives 3-hydroxy-2-imino-l(2f0-pyridinesulfonic acid, which is converted to 2-amino-3-pyridinol(XI-275) on hydrolysis. ... 

Various amino acids can be produced using various raw materials. The sodium aminocarboxylate (Medialan A) and sulfamic acid (Hostapon T) are both synthesized using oleic acid as raw material. The sodium aminocarboxylate (Medialan KA) and sulfamic acid (Hostapon T) are both synthesized using lauric acid as raw material. 

Another organosulfur compound that is used as a herbicide for certain kinds of weed and in nickel electroplating is ammonium sulfamate, the salt of amino-sulfonic acid. Sulfamate is also one of the degradation products of topiramate (2,3 4,5-bis-0-methylethylidene-fi-D-ffuctopyranose sulfamate) that is a sulfa-mate-substituted monosaccharide. 

If organic amino compounds are warmed with excess nitrous acid, the NHa-group is replaced by an OH-group. An analogous deamidation occurs readily in the case of aminosulfonic acid (better known as sulfamic acid). It reacts immediately at room temperature with nitrous acid ... 

Huge success of benzodiazepenes as pharmaceutical scaffolds has prompted preparation and evaluation of het-erocyde-annulated benzodiazepine derivatives. A tandem Michael addition-condensation sequence xmder MW irradiation was also proved to be useful for the synthesis of amino-substituted pyrimidine-fused diazepine derivatives of the type 96 from 4,5,6-triaminopyrimidine and chalcones [57]. Similarly, the pyridine-fused derivatives (97) were prepared xmder MW-assisted solvent and catalyst-free condition [58], Condensation of thiadiazole-annulated phen-ylene diamines with appropriate carbonyl compounds using sulfamic acid as organocatalyst led to the formation of corresponding diazepine derivatives 98 in excellent yields [59] (Figure 4). 

When sulfamate esters 114 are used as substrates, six-membered-ring formation is favored, and results in the selective formation of 1,2,3-oxathiazinane-2,2-dioxide heterocycles 115.251 Nevertheless, five-membered cyclic sulfamidates could be obtained when no alternative cyclization was possible. 1,3-Amino alcohols and related /2-amino acids are thus readily accessible from the same simple alcohols 113 by converting them into sulfamates 114 (Equation (90)). Furthermore, in comparison to the carbamate reaction (Scheme 9), the sulfamate substrates have... 

The sulfamate ester variant of this chemistry has already been shown to be a very powerful protocol for the syntheses of 1,3-amino alcohols and related /3-amino acids (Equation (90)), as well as iminium ion equivalents (Equation (91)). The further showcases of this chemistry are the total syntheses of the bromopyrrole alkaloids, manzacidins A and C (Scheme 13).234 The cyclic sulfamidate 129 was obtained diastereospecifically from sulfamate 128 using intramolecular rhodium-catalyzed G-H insertion. It was then found to react with sodium azide in NfN-dimethylformamide at room temperature after introduction of the Boc-activating group to afford the 1,3-diamino precursor 130 in 78% yield over 3 steps. Four subsequent manipulations afford the target structure 131. 

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