With aminoguanidine

The reaction of 2-nitrosophenols with aminoguanidine nitrate in the presence of nitric acid yields 3-amino-1,2,4-benzotiiazine 4-oxides 154 (75KGS1571). 

Reaction of 2,3-dichlorobenzoyl chloride with cyanide ion leads to the corresponding benzoyl cyanide (141). Condensation of that reactive intermediate with aminoguanidine 142 leads to the hydrazone-like product 143. Treatment with base results in addition of one of the guanidine amino groups to the nitrile function and formation of the 1,2,4-triazine ring. The product, lamo-trigine (144), is described as an anticonvulsant agent [31]. 

Reaction of compounds 168 with aminoguanidine hydrochloride produces ( )-5-guanidylhydrazones 240 (Equation 29) <2000EJM853>. 

Reaction of the 3-deoxypentosulose 1135 with aminoguanidine under physiological conditions gave a mixture of the two triazines 1136 and 1137 (91MI10). 

The reaction of aminoguanidine with ethyl 2,4-dioxopentanoate afforded pyrazole 137 at pH 2. When the reaction was carried out at pH 4, pyrazolo[l,5- /]-l,2,4-triazine (136) was formed upon further reaction of 137 with aminoguanidine (76MI2) (Scheme 19). 

Several syntheses of indiplon have been described and two routes are shown in Scheme 15.5 (Sorbera et al., 2003 Dusza et al., 2002). Treatment of acetophenone 26 with refluxing dimethylformamide dimethylacetal (DMF-DMA) provided enamide 27. Alkylation of the amide with methyl iodide using NaH in DMF afforded 28. 3-Ketonitrile 29 was treated with DMF-DMA to give enamide 30. Cychzation with aminoguanidine produced aminopyrazole 31. The condensation of enamide 28 with aminopyrazole 31 in acetic acid furnished indiplon (4). Alternatively, enamine 28... 

The second important reaction path similar to AT synthesis starts with aminoguanidine derivatives (in this case part of a HP) and proceeds via condensation with a synthon Z (see principle in Scheme 8). In a first step l,2,4-triazolo-[4,3-a]pyrimidines (15) are formed these are often isolable and nearly always transformable into the more stable TPs by Dimroth rearrangement. 

Guanyl azide is then isomerized to aminotetrazole (V) which undergoes diazo-tization and couples with aminoguanidine as stated above. 

Naphthoquinone 1-oxime (772) reacts with aminoguanidine (773) and similar compounds to give 2-aminonaphtho[ 1,2-e][1,2,4]triazine 1-oxides (774). 1-Hydroxy-naphtho[l,2-e][l,2,4]triazin-2-ones can be prepared in an analogous reaction <78HC(33)189, p. 728). 

In the presence of mineral acids, sodium nitrite reacts in a different manner with aminoguanidine, and guanyl azide is formed. 

Wada K., Chatzipanteli K., Kraydieh S., Busto R., and Dietrich W. D. (1998) Inducible nitric oxide synthase expression after traumatic brain inj ury and neuroprotection with aminoguanidine treatment in rats. Neurosurgery 43, 1427-1436. 

In the area of hydrometallurgy, Cu2+ and Au(CN)2 salts could be selectively sorbed from aqueous solutions with polyacrylamide-based copolymers containg aminoguanidine units. Porous copolymers of acrylonitrile, divinylbenzene and vinylacetate were derivated with aminoguanidine.15 Alternatively, methacrylate-based copolymers were transamidated with the same base16 to give polyacrylamide-type resins (Figure 11). 

Several reports are available on the condensation of nitromalonaldehyde with hydrazines to give 4-nitropyrazole derivatives (47) [Eq. (14)].39-41 The reaction of sodio-nitromalonaldehyde with aminoguanidine in the presence of acid directly yields l-guanyl-4-nitropyrazole (48 R = C(NH)NH2).42 43... 

The carbonyl groups in the derivatives of 159 undergo mono- and diaddition reactions. For example, mono- and diguanylhydrazones are prepared by heating 159 with aminoguanidine salts.102 Treatment of 174... 

The reaction of monosubstituted glyoxals (455) with aminoguanidine (460a) has been extensively studied. Either 5- or 6-substituted 3-amino-1,2,4-triazines can be obtained depending on the reaction conditions. N-Alkyl-substituted aminoguanidines with 1,2-dicarbonyl compounds condense to give 3-alkylamino-l,2,4-triazines, while... 

Reactions of 5-nitrosobarbituric acids with aminoguanidine, of 5-phen-ylazobarbituric acids with phenethylamine, and of 5-arylmethylene-aminobarbituric acid with NBS or thionyl chloride afford isofervenu-lins, 8-phenyl-xanthines, and oxazolo[5,4-t/]pyrimidines, respectively [75BCJ725, 75BCJ1679 77H(6)689, 77H(6)1901, 77H(6)1919 78CPB765] (Scheme 75). 

Methoxyvinyl trifluoromethyl ketones 772 underwent regiospecific cyclization with aminoguanidine to give trifluoromethyl alcohols 773, which were dehydrated to give trifluoromethylated 2-[l//-pyrazol-l-yl]pyrimidines 774 (Scheme 97) <2001S1505>. 

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