Hydrazine hydrate, reaction with

Triazole has been prepared by the oxidation of substituted 1,2,4-triazoles, by the treatment of urazole with phosphorus pentasulfide, by heating equimolar quantities of formyl-hydrazine and formamide, by removal of the amino function of 4-amino-l,2,4-triazole, by oxidation of l,2,4-triazole-3(5)-thiol with hydrogen peroxide, by decarboxylation of 1,2,4-triazole-3(5)-carboxylic acid, by heating hydrazine salts with form-amide,by rapidly distilling hydrazine hydrate mixed with two molar equivalents of formamide, i by heating N,N -diformyl-hydrazine with excess ammonia in an autoclave at 200° for 24 hours, and by the reaction of 1,3,5-triazine and hydrazine monohydrochloride. ... 

Hydrate A compound containing bound water such Bad2 H20,66 Hydration Reaction with water, 602 Hydrazine, 560... 

Hydrazine hydrate reacts with a-hydroxyacids to give the A -aminodihydrotriazole which is diazotised with sodium nitrite in HCl to the 3,5-disubstituted triazole enantiomer (Scheme 24) <87H(26)989>. These triazoles were converted to macrocyclic derivatives (see Section 4.02.12.3). The ketals of a-oxoesters undergo the same series of reactions to give, after hydrolysis, the 3,5-dicarbonyl derivatives (Scheme 25) <92S398>. 

Mercuric Oxide HgO Hydrazine. Explosive reaction with hydrazine hydrate.7... 

The hydrazino derivative (106), obtained from the chloro-compound (123) (see Section 6.14.7.5) by reaction with ethanolic hydrazine hydrate, reacts with DMF-dimethyl acetal in hot xylene to give 5,7-diphenyl-7A -[l,2,4]triazolo[3,4-c][l,2,4]thiadiazine 7-oxide (107 72%) (Equation (9))... 

Hydrazine hydrate reacts with 1,3-butadiyne moieties in competition with the carbonyl groups. Therefore, tosylhydrazine is employed for the selective reaction with the latter. The sodium salts of the resulting tosylhydrazones are heated to give the diazo compounds 16,18, and 20 [8, 10]. As some of the 1,3-butadiyne derivatives in Table 11-2 undergo spontaneous polymerization in the solid state (see Section 11.4.1), they have to be kept in solution. 1,3-butadiyne units are also known to react with diazo groups [11] and therefore the diazo compounds such as 16, 18, and 20 must be kept refrigerated. 

Hydrazine hydrate reacts with 3-benzoylimino-5,6-dihydro-3/f-imidazo[2,l-c][l,2,4]dithiazole (19) opening the dithiazole ring and forming a triazole ring, giving (123). Reaction with aniline leads to the formation of imidazolidine-2-thione (120) and l-benzoyl-3-phenylthiourea (124) (Scheme 6)... 

The reaction between metal thiocyanates and hydrazinium thiocyanates cannot be used to prepare hydrazinium metal thiocyanate complexes. Consequently, an alternate method is employed, namely, the decomposition of hydrazinium metal hydrazine carboxylates with dilute thiocyanic acid (<5%) [27,28]. Hydrazinium metal hydrazine carboxylates complexes N2H5M(N2H3C00)3 H20, where M = Co and Ni, are prepared from metal nitrates, sulfates, or chlorides and hydrazine hydrate saturated with carbon dioxide. The dilute thiocyanic acid is prepared by adding barium thiocyanate trihydrate to dilute sulfuric acid. 

Dissolve 10 g. of chloro- 2,4-dinitrobenzenet in 50 ml. of dioxan in a 250 ml. conical flask. Dilute 8 ml. of hydrazine hydrate with an equal volume of water and add this slowly with shaking to the dioxan solution, keeping the temperature between zo " and 25°. Heat under reflux for 10 minutes to complete the reaction and then add 5 ml. of ethanol and heat again for 5 minutes. Cool and filter oflF the orange 2,4-dinitrophenylhydra-zine. Recrystallise the dry product from ethyl acetate m.p. 200° (decomp.). Yield, 7 g. 

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... 

Girard s reagent T is carbohydrazidomethyltrimethylammonium chloride (I) and is prepared by the reaction of the quaternary ammonium salt formed from ethyl chloroacetate and trimethylamine with hydrazine hydrate in alco-hoUc solution ... 

Girard s reagent P , C5H5NCH2C0NHNH2 C1. In a 1-htre threenecked flask, equipped as in the previous preparation, place 200 ml. of absolute ethyl alcohol, 63 g. (64 -5 ml.) of pure anhydrous pyridine and 98 - 5 g. (84 5 ml.) of ethyl chloroacetate. Heat the mixture under reflux for 2-3 hours until the formation of the quaternary salt is complete acidify a small test-portion with dilute sulphuric acid it should dissolve completely and no odour of ethyl chloroacetate should be apparent. Cool the mixture in ice and salt. Replace the thermometer by a dropping funnel, and add a solution of 40 g. of 100 per cent, hydrazine hydrate in 60 ml. of absolute ethanol all at once. A vigorous exothermic reaction soon develops and is accompanied by vigorous effervescence. The pro duct separates almost immediately. When cold, filter with suction, wash... 

With Stirring, hydrazine hydrate (4 ml in 30 ml of THh ) was added over 60 min. The reaction mixture was then cooled to room temperature and filtered through Celite. The filtrate was concentrated in vacuo and the residue purified by chromatography through silica gel using 10% ether in hexane for elution. The fractions containing product were combined and evaporated to give the product as a clear oil (2.94g, 50%). 

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