Trimethylhydrazinium iodide

Trimethylhydrazinium iodide is a novel, highly reactive reagent for aromatic animation via VNS, as shown in Eq. 9.49, in which the regioselectivity is different from that obtained with other reagents.82... 

Recently, TATB (14) has been synthesized by treating TNB and picramide (53) with VNS aminating agents like 4-amino-1,2,4-triazole (ATA) and 1,1,1-trimethylhydrazinium iodide (TMHI) in the presence of sodium methoxide in Hydroxylamine has been used... 

Except for the substrate RA, the radical cation of reagent (CH3)3N+-N H has been registered and identified in the reaction mixture of 2-phenyl-4-nitro-l,2,3-triazole with 1,1,1-trimethylhydrazinium iodide (Fig. 3.4) [274, 277],... 

Fig. 3.4 The ESR spectrum recorded in the reaction of 2-phenyl-4-nitro-1,2,3-triazole with 1,1,1-trimethylhydrazinium iodide in r-BuOK-DMSO after 25 minutes (top) and after 45 minutes (bottom left) from the beginning of reaction, computer simulation of ESR signal of radical anion (bottom right)...

Reaction of l-methyl-4-nitropyrazole with 1,1,1-trimethylhydrazinium halides in the presence of sodium methoxide or potassium fert-butoxide afforded 5-amino-l-methyl-4-nitropyrazoles <1999CHE1109>. Specifically, the primary radical anions of substrate in the vicarious nucleophilic substitution of hydrogen in 1-methyl-4-nitropyrazole 192 with 1,1,1-trimethylhydrazinium iodide yielded 5-amino-l-methyl-4-nitropyrazole 193, which was studied by electron spin resonance (ESR) (Equation 31) <2005MRC1023>. Reaction of 3,5-dinitropyrazole 194 with trimethylhydrazinium iodide in DMSO afforded 4-amino-3,5-dinitro-l//-pyrazole 195 via another vicarious nucleophilic substitution (Equation 32) <2001JHC1227>. 

Aryl-4,6-dinitroindoles (46) have also been explored as substrates for VNS reactions. They can be aminated using 1,1,1-trimethylhydrazinium iodide (TMHI) regioselectively at C-7 [27]. 

N-Phenyl-N-isopropylacrylamide refluxed overnight with 2 equivalents 1,1-di-methylhydrazine, coned, in vacuo, and treated with methyl iodide in ether 2- [ (2-isopropylphenylcarbamoyl) ethyl] -1,1,1-trimethylhydrazinium iodide (Y ca. 100%) refluxed IShrs. with Na-methoxide in ethanol N-phenyl-N-iso-propyl-2-aziridinecarboxamide (Y 57%). F. e. s. G. R. Harvey, J. Org. Chem. 33, 887 (1968). 

Tetranitro derivative 90 (z-TACOT Section 12.10.15.5) treated with methanolic sodium methoxide at ambient temperature does not lead to simple product of nucleophilic substitution of a nitro group but provides compound 92. Its formation can be rationalized by introduction of the methoxy group into the 1-position, followed by scission of the remote triazole ring of 91 to give the final product. Compound 90 subjected to the vicarious nucleophilic substitution (VNS) conditions using either hydroxylamine or trimethylhydrazinium iodide gives a very insoluble red solid, which was identified as l,3,7,9-tetraamino-2,4,8,10-tetranitrobenzotriazolo[2,l- ]benzotriazole 93 (Scheme 5) <1998JOC3352>. 

This direct amination process has found wide application in synthesis. For instance, double VNS amination of 2,4,6-tiinitroaniline with an excess of trimethylhydrazinium iodide is an efficient method of manufacturing of 2,4,6-trinitro-l,3,5-triaminobenzene, a highly energetic material (Scheme 11.46) [70b]. 

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