Ethylenediamine dihydrochloride

Nitrite can be deterrnined by reaction with sulfanilamide to form the diazo compound, which couples with /V-(1-naphthyl)ethylenediamine dihydrochloride to form an intensely colored red azo dye. Nitrate can be deterrnined in a similar manner after reduction to nitrite. Suitable reducing agents are cadmium filings or hydrazine. This method is useful at a nitrogen concentration of 10 -lO " M. 

Spray solution Ila Dissolve 1 g A -(l-naphthyl)ethylenediamine dihydrochloride in 10 ml water and make up to 100 ml with ethanol [11]. 

Spray solution Ilb Dissolve 1 g 7V-(l-naphthyl)ethylenediamine dihydrochloride in 50 ml dimethylformamide and 50 ml hydrochloric acid (< Hci = 4 mol/1) with warming. If the cooled solution is not clear it should be filtered. A pale violet coloration does not interfere with the reaction [4]. 

After cooling, unreacted ethylenediamine is neutralized in a cooling mixture with the absolute ethanolic hydrochloric acid, filtered off from any components that are insoluble in ethanol and approximately two-thirds of the solvent filtered off under suction in a water jet pump vacuum. Residual quantities of ethylenediamine dihydrochloride are precipitated in fractions by the careful addition of ethyl methyl ketone, after which the imidazoline hydrochloride is separated off by the addition of dry ether. Following repeated recrystallization from ethanol ether, 2-[0(-(2,6-dichlorophenoxy)ethyl] -A -imidazoline hydrochloride is obtained in the form of small white crystals melting at 221°C to 223°C. 

In this case the nitrite ion, under acidic conditions, causes diazotisation of sulphanilamide (4-aminobenzenesulphonamide) to occur, and the product is coupled with N-( 1 -naphthyl)ethylenediamine dihydrochloride. 

N- (1-naphthyl) -ethylenediamine dihydrochloride solution (B). Dissolve 0.3 g of the solid reagent in 100 mL of 1 per cent v/v hydrochloric acid. 

Spray solution 4 Dissolve 100 mg N-(l-naphthyl)-ethylenediamine dihydrochloride in 100 ml ethanol. The solution should always be made up fresh even though it remains stable for several days. 

Dipping solution 3 Dissolve 0.5 g N-(l-naphthyl)-ethylenediamine dihydrochloride in 5 ml water and make up to 50 ml with ethanol [1]. 

Titanium(III) chloride (particularly in slightly alkaline medium) reduces the p-nitro groups of the thiophosphate insecticides to amino groups, which are then reacted with nitrite in acid mediiun in a second step to yield a diazonium compound as intermediate. This is then coupled to N-(l-naphthyl)-ethylenediamine dihydrochloride to yield an azo dye [3]. In the case of benzodiazepines the first reaction step includes an additional acid hydrolysis to the corresponding benzophenone derivative [2]. 

N-(l-Naphthyl)-ethylenediamine dihydrochloride Hydrochloric acid (327o)... 

E.K.C. 4835 is N-(l -naphthylj-ethylenediamine dihydrochloride. Recent chromatographic evidence indicates that the final colored reaction product from technical grade parathion may be a mixture of at least three and possibly four components. 

Spencer and Brewer [111] have reviewed methods for the determination of nitrate in seawater. Classical methods for determining low concentrations of nitrate in seawater use reduction to nitrite with cadmium/copper [ 112,116,117] or zinc powder [113] followed by conversion to an azo dye using N- 1-naphthyl-ethylenediamine dihydrochloride and spectrophotometric evaluation. Malho-tra and Zanoni [114] and Lambert and Du Bois [115] have discussed the interference by chloride in reduction-azo dye methods for the determination of nitrate. 

N-(l-naphthyl) ethylenediamine dihydrochloride (NEDA). Prepare 100 mL of a 0.5% aqueous solution of NEDA. The solution is stable for at least a month if refrigerated and protected from light. It is a poison—use gloves. 

Hermnsky SJ, Yang R SH, Garman RH, et al Chronic toxicity and carcinogenicity studies of ethylenediamine dihydrochloride by dietary incorporation in Fischer 344 rats. Food Chem Toxicol 37(7) 765-76, 1999... 

In the presence of FeCls and chlorine, ethylenediamine dihydrochloride formed 3,4-dichloro-l,2,5-thiadiazole (74%) (1989DDP271425). 

An alternative method for the preparation of the dihydrodiazepinium salt 5 involves the reaction of ethylenediamine dihydrochloride with ace-tylacetone [67JCS(C)2400]. Dihydrodiazepines have also been obtained from reactions between diketones and ethylenediamine (free base) in ethanol (71 Mil 78JIC577 78MI1). 

N-(a-Naphthyl)ethylenediamine dihydrochloride [1465-25-4] M 291.2, m 188-190°, Crystd from water. 

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