Preparation from Hydrazine Sulfate

Preparation from Hydrazine Sulfate. Sixty-five grams of hydrazine sulfate (0.5 mol) is added to a mixture of 30 g. of glacial acetic acid (0.5 mol) in 1000 ml. of water. Eighty-nine grams of potassium cyanate (1.1 mol) dissolved in 300 ml. of water is added to this solution portion-wise with constant stirring. Considerable gas evolution takes place, and the temperature rises to about 40°. The acetic acid serves to adjust the final pH to approximately 4.8. 

After the mixture has been allowed to digest for 4 hours at room temperature with constant stirring, the biurea is filtered by suction and washed with 300 ml. of water, followed by ethanol and ether. The dry product should weigh from 53 to 55 g. (90 to 93 % yield). The biurea is quite pure and need not be recrystallized. 

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Preparation from Hydrazine Hydrate. Hydrazine hydrate may be substituted for hydrazine sulfate in the preparation of biurea. In this case it is necessary to supply enough additional acetic acid to compensate for the absence of sulfuric acid. Thus, 29 g. of 85% hydrazine hydrate (0.5 mol) and 90 g. of glacial acetic acid (1.5 mol) are dissolved in 500 ml. of water. Eighty-nine grams of potas-... 

The preparation of -azoisobutyronitrile by oxidation of the corresponding crude hydrazo compound with chlorine in aqueous solution is described in the Houben-Weyl compendium.11 <, -Hydrazoisobutyronitrile [N,N bis-(l-cyano-l-methylethyl)hydrazine] is readily accessible from hydrazine sulfate, NaCN, and acetone in water.11 ... 

The compound can be prepared from 2,4,6-trinitrophenol (picric acid [88-89-1]) by reduction with sodium hydrosulfide (163), with ammonia —hydrogen sulfide followed by acetic acid neutralization of the ammonium salt (164), with ethanolic hydrazine and copper (165), or electrolyticaHy with vanadium sulfate in alcoholic sulfuric acid (159). Heating 4,6-dinitro-2-benzamidophenol in concentrated HQ. at 140°C also yields picramic acid (166). 

A process for the preparation of 3(5)-methylpyrazole (13) from enynamines and hydrazine sulfate (80°C, H" ", Et0H/H20, 2 h, yield 72%) has been described (69ZOR1179). 

B. t-Bulyl carbazate. In a 1-1. Erlenmeyer flask are placed 388.4 g. (2.0 moles) of phenyl <-butyl carbonate and 120.2 g. (2.4 moles) of a 64% hydrazine solution (Note 6). The mixture is swirled by hand and heated on a hot plate. When the internal temperature reaches 75-80°, it then rises rapidly and spontaneously to 104—110°, the two layers forming a dear solution. The solution is allowed to cool overnight. The mixture is then diluted with 500 ml. of ether and transferred to a separatory funnel in which it is shaken vigorously for about 10 minutes with a solution prepared from 160 g. (4.0 moles) of sodium hydroxide and 1.2 1. of water. The resulting two layers are placed in a 2-1. continuous extractor and extracted for 48 hours with ether. The ether solution is dried over magnesium sulfate, and the ether is removed by distillation from a water bath. The last portions of ether are removed with the aid of a water aspirator. The residual oil is then distilled using a Claisen flask with an air bath maintained at 115-125°. After 1 or 2 drops of fore-run the carbazate is collected at 61-65° (1.2 mm.), 24d 1.4518. The yield is 235-256 g. (89-97%) (Note 7). 

Other Applications. Hydioxykmine-O-sulfonic acid [295043-8] has many applications in the area of organic synthesis. The use of this material for organic transformations has heen thoroughly reviewed (125,126). The preparation of the acid involves the reaction of hydroxylamine [5470-11-1] with oleum in the presence of ammonium sulfate [7783-20-2] (127). The acid has found application in the preparation of hydrazines from amines, aliphatic amines from activated methylene compounds, aromatic amines from activated aromatic compounds, amides from esters, and oximes. It is also an important reagent in reductive deamination and specialty nitrile production. 

One series of POD has been prepared from the corresponding dicarboxylic acid/acid chlorides and hydrazine sulfate in polyphosphoric acid (PPA) (50,51), one of the most common techniques for this type of backbone. 

Dimethylpyrazole has been prepared from acetylacetone and hydrazine hydrate in ethanol3 or hydrazine sulfate in aqueous alkali.4 6 The latter method is preferred, because the reaction with hydrazine hydrate is sometimes violent.3 4 3,5-Dimethyl-pyrazole has also been prepared by hydrolysis and decarboxylation of the 1-carbamido- or 1-carboxamidine derivatives, obtained by reaction of semicarbazide 7 or aminoguanidine 8 with acetylacetone. 

The yield from this reaction is greatest if the medium is alkaline, for nitrous acid attacks hydrazoic acid oxidizing it with the liberation of nitrogen. If hydrazine sulfate is used in the mixture, the resulting hydrazoic acid is not available for the preparation of lead azide until it has licen distilled out of the solution. (Lea[Pg.465]

Tetrafluoropyrazine with hydrazine gives 2,3,5-trifluoro-6-hydrazinopyrazine which on warming with aqueous copper sulfate gave trifluoropyrazine and 2,3-difluoro-5-hydrazino-6-methoxypyrazine similarly treated gave 2,3-difluoro-5-methoxypyrazine (885), but 2,3,5-trichloropyrazine could not be prepared from... 

Synthesis of heterocycles. 3,5-Dimethylpyrazole is prepared from acetylacetone and hydrazine sulfate in aqueous alkali (the reaction with hydrazine hydrate is sometimes violent). ... 

Su ate esters. Baumgarten showed that the reagent sulfates substances such as hydrazine, diethylamine, phenol, and naphthalene. It has been used in preparation of carbohydrate sulfate esters, sterol sulfate esters, phenol sulfate esters. 2-Hydroxy-3-alkyl-l,4-naphthoquinone antimalarials can be separated from metabolites hydroxylated in the side chain by conversion of the hydroxylated metabolites into water-soluble sulfate esters and extraction with water. Hydroxy-hydrolapachol (1), which was identified as a metabolite of hydrolapachol and which... 

This type of compound was prepared from aldehydes 216 by conversion into the bis(arylhydrazone) 225, which, upon reaction with copper sulfate, afforded the corresponding triazoles 227 (Scheme 48). When 216 was allowed to react with amines or hydrazines having substituents that differ from that in 216, the corresponding mixed bis(hydrazones) 228-230 were prepared. Attempted oxidation of bis(benzoylhydrazone) 231 with iodine and mercuric oxide to give 232 was investigated (80MI7). 

The methods previously reported for the preparation of tetrachloroplatinic(II) acid1 and platinum(II) chloride are laborious and difficult to control. Platinum(II) chloride has been prepared by the thermal decomposition of ammonium hexachloroplatinate(IV)2 or of anhydrous platinum-(IV) chloride.3 According to a recent report,4 hydrazine sulfate is an effective reducing agent for the preparation of tetrachloroplatinate(II) salts from the corresponding hexachloroplatinate(IV) salts. This procedure has been extended to the preparation of aqueous tetrachloro-platinic(II) acid and solid platinum (II) chloride. 

In 1938, Egami reported that n-glucose monosulfate (prepared from D-glucose by direct sulfation) is hydrolyzed slowly in aqueous solutions of hydrazine or related organic reagents. Further studies educed the fact that a purified preparation of D-glucose 6-sulfate is desulfated only slowly by M hydrazine at pH 6, whereas an impurity, present in crude preparations of the 6-sulfate, is hydrolyzed at a much higher rate. ... 

Very reactive substances are treated with NBS alone, but in other cases a radical-former is added. The favored radical activator for bromination of olefins by NBS is 2,2/-azoisobutyronitrile, 1 part per 100-1000 parts of NBS. This nitrile is obtained by reaction of bromine water with 2,2 -hydrazoiso-butyrodinitrile, which is prepared from acetone, KCN, and hydrazine sulfate in warm water365 (see also Dox366). The decomposition temperature of dibenzoyl peroxide is higher than that of 2,2 -azoisobutyrodinitrile, and about 30° above the boiling point of CC14. 

Aminoguanidine can be prepared in high yield by addition of hydrazine to cyanamide a simple procedure starting from disodium cyanamide and hydrazine sulfate is given by Fantl and Silbermann.46... 

If hydrazoic acid is available, hydrazine azide is made by simply admixing the acid with an equimolar quantity of hydrazine, either by bubbling in the HN3 gas [52] or by using aqueous or ethereal HN3 solutions. In the latter case, the hydrazine azide is precipitated [197,311]. The preparation from sodium azide and hydrazine salt is more convenient. According to one source [313], 17 g hydrazine sulfate, 17 g sodium azide, and 4 g hydrazine are refluxed in 2 liters M-butanol at 117°C for 15 min. The liquid phase is then separated and cooled to 5°C when N5H5 is precipitated. 

A suspension of 130 g. of dry hydrazine sulfate In 600 g. of dry pyridine is prepared. Chlorosulfonic acid (300 g.) is added in portions from an addition funnel with stirring and cooling. Finally, the mixture is heated to 90-100°C on a water bath. It is then allowed to cool, and alcohol Is added with shaking. The crystalline mass that separates Is suction-filtered. For purification the pyridine salt so obtained is redissolved in a small amount of water, some alcohol is added, and the mixture is evaporated in a desiccator until copious crystallization is induced. The crystals are then suction-filtered. This pyridine salt, in the form of needles with a silken sheen, can be used for the preparation of potassium azodisulfonate. The compound is readily soluble in water and very slightly soluble in alcohol. For the preparation of the potassium hydrazinedisulfonate, the crystals need not be isolated. Thus, Instead of alcohol, 300 g. of ice and as much potassium hydroxide solution (d 1.39) as needed to make the solution barely alkaline are added to the impure mixture after coolii. The precipitated salt is suction-filtered and washed with cold water. The yield is about 200 g. 

The preparation of tebufenpyrad and tolfenpyrad (see below) are outlined in Scheme 28.3.4. The pyrazole ring is prepared from a Claisen condensation of 2-butanone with diethyl oxalate followed by treating the resulting acylpyruvate with hydrazine [45, 46]. The pyrazole ring is then alkylated with dimethyl sulfate at 50-60 °C without base to give, selectively, the l-methylpyrazole-5[Pg.893]

Complexation of nitrogen by Cu " " has been used to advantage in several cases. The selective hydrolysis of a-aminodiesters is guided by chelation to nitrogen and activation of the vicinal ester group (eq 4). Cycloreversions of 2-azanorbomenes to give primary amines are catalyzed efficiently by copper sulfate (eq 5). Copper sulfate (or other Cu " " sources) facilitates the preparation of diimide from hydrazine by complexation with nitrogen. See also copper(II) acetate. 

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