Thiourea S-dioxides

Formamidine sulfmie acid (thiourea-S-dioxide) [1758-73-2] M 108.1, m 124-126"(dec). Dissolve it in five parts of aqueous 1 1% NaHS03 at 60-63" (charcoal), then allow it to crystalUse slowly, with agitation, at 10". Filter and dry it immediately at 60" [Koniecki Linch Awa7 Chem 30 1134 7958]. [Beilstein 3136,3IV 145.]... 

N2O2SC a-Diazosulfones a-Ketosulfone hydrazones Monosulfonylcarbodimides Sulfonylamidines Sulfonic acid amidines 5 N-Sulfonylformamidines 20 N -Sul fony Icyanamides Sulfonylformaldehyde hydrazones Sulfonylhydrazones Thiourea S-dioxides... 

A new method for the reductive conversion off-keto- -nitroesters to pyrroles involves the use of formamidinesulfinic acid (thiourea S,S-dioxide) as the reducing agent. <95TL9469> The ester substituent seems to be required since no reaction occurred with simple a-nitroketones. 

DiarylteUnrinm trichlorides and dichlorides (Section 3.2) can be converted to diorganyltellurides and ditellnrides npon treating with redncing agents such as sodium sulfide, potassium hydrogensulfite, hydrazine, or thiourea S,S-dioxide. A typical example is shown in Eg. (6). ... 

A number of procedures have been reported for the reduction of sulfoxides to sulfides which do not appear to fit the above broad categories but which are also versatile procedures, employing relatively low temperatures and short reaction times. For example, Drabowicz and Mikolajczyk used the system thiourea S,S-dioxide-iodine in refluxing acetonitrile to reduce several sulfoxides to sulfides in yields of 89-95%. The sulfinic acid (6) is quite well known as a reducing agent but the catalytic role played by... 

Thiocarbonyl compounds are also substrates of monooxygenases, forming S-monoxides (sulfmes, reaction 3-A) and then S-dioxides (sulfenes, reaction 3-C). Asa rule, these metabolites cannot be identified as such because of their reactivity. Thus, S-monoxides rearrange to the correspondingcarbonyl by expellinga sulfur atom (reaction 3-D). This reaction is known as oxidative desulfurationand occurs in thioam-ides and thioureas (e.g., thiopental). As for the... 

CAS 1758-73-2 EINECS/ELINCS 217-157-8 Synonyms Aminoiminomethane sulfinic acid Formamidine sulfinic acid Thiourea S,S-dioxide... 

Thiourea S,S-dioxide. See Thiourea dioxide Thiovanic Acid] Thiovanic acid. See Thioglycolic acid... 

The Hurd-Mori reaction,where a tosylhydrazone is converted by thionyl chloride to the corresponding thiadiazole, involves the formation of a 1,2,3-thiadiazole-3,3-dioxide. In one example, this type of compound was isolated and subsequently deoxygenated with thiourea <1991PS175>. There have been no further reports of S-linked sulfoxide or sulfone derivatives of 1,2,3-thiadiazoles since the publication of CHEC-II(1996). 

Thiourea dioxide (TUDO, HN=C(NH2)S(0)0H)/Na0ff 23.23 Hydride transfer reagents... 

The use of sodium dithionite (Na2S204) and thiourea dioxide (TUDO HN=C(NH2)S(0)0H) has been introduced later as a reducing agent for the preparation of sodium telluride in an aqueous medium, followed by reaction with n-alkyl halides to give dialkyl teUiirides. - ... 

The utility of urca.s and thioureas as substrates for making imidazoles is limited by the fact that the imidazole 2-substituent can only be an oxygen or sulfur function. Synthetic methods involving ureas and thioureas will also be discussed in Section 4.1, but some cyclizations of suitably functionalized species fall under the present heading. Appropriately substituted ureas and thioureas can be made from isocyanates and primary amines [36-38], from isocyanates and hydrazines [39] or thiocyanates and hydrazines [40], from or-aminonitrilcs and carbon dioxide [41] and by heating l,3,4-oxadiazol-2-oncs with amino acids [42]. Some of the substrates prepared in these ways, though, lead ultimately to reduced imidazoles such as hydantoins. Cyclizations arc usually acid catalysed, but they can also be thermal [43]. 

Condensation of 2-aminobenzenesulfonamide (175) with an alkyl or acyl isothiocyanate in the presence of triethylamine affords a 3-alkylamino- or 3-acylamino-2ff-l,2,4-benzothiadiazine 1,1-dioxide (177) via cyclization of a thiourea intermediate (176 X = S) (Scheme 27) <90MI 6l4-04>. In contrast, the corresponding ureas (176 X = O) in hot DMF suffer elimination of the alkylamine residue to form 277-l,2,4-benzothiadiazin-3(4Ff)-one (178) in 90% yield <90JHC1909>. 

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