Hydrazines sources

Figure 2.2 Increase in liver weight and liver triglycerides caused by hydrazine. Source. From Ref. 3.

The reaction between a carbonyl group and hydrazine is a classical reaction but in this case we obtained a bis(3-cyano-3,5,5-trimethylcyclohexylidene) azine which was a new product. The preferred hydrazine source was hydrazine hydrate since it is an industrial product easy to use. In order to obtain an industrially viable process different parameters of the reaction have been optimized. 

Urea Process. In a further modification of the fundamental Raschig process, urea (qv) can be used in place of ammonia as the nitrogen source (114—116). This process has been operated commercially. Its principal advantage is low investment because the equipment is relatively simple. For low production levels, this process could be the most economical one. With the rapid growth in hydrazine production and increasing plant size, the urea process has lost importance, although it is reportedly being used, for example, in the People s RepubHc of China (PRC). 

Cross-linked PVP can also be obtained by cross-linking the preformed polymer chemically (with persulfates, hydrazine, or peroxides) or with actinic radiation (63). This approach requires a source of free radicals capable of hydrogen abstraction from one or another of the labile hydrogens attached alpha to the pyrrohdone carbonyl or lactam nitrogen. The subsequently formed PVP radical can combine with another such radical to form a cross-link or undergo side reactions such as scission or cyclization (64,65), thus ... 

Isoxazoles (478) in the presence of base undergo ring opening to a-ketonitriles (479). When the reaction was carried out in the presence of hydrazines, 5-aminopyrazoles (480) were obtained. The reaction is also a convenient source of imidazoles, For example, when the 1,2-benzisoxazole (481) was treated with phenylhydrazine, decarboxylation initially occurred with subsequent ring closure to (482) (see Chapter 4.16). 

Phenyl-l,2-dithiolylium salt (483) with hydrazine, methylhydrazine or phenylhydrazine yielded the corresponding pyrazole (485) via the intermediates (484a-c). The ring-fused system (486) is a convenient source of the ring-fused pyrazole (487) when treated with hydrazine (see Chapter 4.31). 

In a typical experiment, triethylene glycol was treated with two equivalents of sodium toluenesulfonamide in dry DMF solution. After 6 h at reflux, the solution was distilled and product obtained by a standard work-up procedure. By this procedure, 9 was obtained in about 10% yield. The transformation is illustrated below as Eq. (4.10). Note also that Vogtle and his coworkers have also utilized phthalimide as a source of nitrogen in the preparation of such azacrown precursors as H2N(CH2CH2 0)2CH2CH2NH2 In such reactions, a standard hydrazine cleavage was used to remove the phthaloyl residue. 

Pd-C, ROH, HCO2NH4, hydrazine or sodium hypophosphite, 42-91% yield. 2-Benzylaminopyridine and benzyladenine were stable to these reaction conditions. Lower yields occurred because of the water solubility of the product, thus hampering isolation. Cyclohexene can be used as a hydrogen source in the transfer hydrogenation. ... 

With Af-acyl or Af-sulfonyl hydrazines as nucleophiles, Zincke salts serve as sources of iminopyridinium ylides and ylide precursors.Reaction of the nicotinamide-derived Zincke salt 8 with ethyl hydrazino urethane 42 provided salt 43, while the tosyl hydrazine gave ylide 44 (Scheme 8.4.14). ° Benzoyl hydrazines have also been used in reactions with Zincke salts under similar conditions.Af-amino-1,2,3,6-tetrahydropyridine derivatives such as 47 (Scheme 8.4.15), which showed antiinflammatory activity, are also accessible via this route, with borohydride reduction of the initially formed ylide 46. ... 

N-Nilrosoamines are reduced easily lo ihe hydrazine and, if continued, lo the amine (62). Early workers ruled out cleavage of dimeihylhydrazine as the source of dimethylamine in hydrogenation of N-nitrosodimethylamine since liule ammonia was found the letramethylietrazene was implicated in the hydrogenolysis (fSI). Palladium-on-carbon under mild conditions is used for industrial production of dialkyl hydrazines from N-nitrosoamines. 

Synthesis gas is a major source of hydrogen, which is used for producing ammonia. Ammonia is the host of many chemicals such as urea, ammonium nitrate, and hydrazine. Carbon dioxide, a by-product from synthesis gas, reacts with ammonia to produce urea. 

Ammonia is the precursor for many other chemicals such as nitric acid, hydrazine, acrylonitrile, and hexamethylenediamine. Ammonia, having three hydrogen atoms per molecule, may be viewed as an energy source. It has been proposed that anhydrous liquid ammonia may be used as a clean fuel for the automotive industry. Compared with hydrogen, anhydrous ammonia is more manageable. It is stored in iron or steel containers and could be transported commercially via pipeline, railroad tanker cars, and highway tanker trucks. The oxidation reaction could be represented as ... 

Heat of vaporization, 66 see also Vaporization Helium, 91 boiling point, 63 heat of vaporization, 105 interaction between atoms, 277 ionization energy, 268 molar volume, 60 on Sun, 447 source, 91 Hematite, 404 Hemin, structure of, 397 Hess s Law, 111 Heterogeneous, 70 systems and reaction rate, 126 n-Hexane properties, 341 Hibernation, 2 Hildebrand, Joel H.. 163 Holmium, properties, 412 Homogeneous, 70 systems and reaction rate, 126 Hydration, 313 Hydrazine, 46, 47, 231 Hydrides of third-row elements, 102 boiling point of. 315 Hydrocarbons, 340 unsaturated, 342... 

Amino-5-hydrazinopyrazole dihydrochloride 300 is a good source for the synthesis of this type of heterocyclic compound [78JCS(P1)885] and it was prepared by reaction of malononitrile with two equivalents of hydrazine. Reaction of 300 with ethyl pyruvate afforded 301. Unstable hydra-zone 302 formed when 300 was boiled with diacetyl rapidly cyclized to 303. Reaction of 300 with benzil gave 304 directly, which gave an acetyl derivative and resisted reductive deamination. On the other hand, a polymer was isolated from the reaction of 300 with glyoxal (Scheme 65). 

Another probable source of the relatively high yield of N2O observed in this experiment is reaction of OH with the nitroso-hydrazine ... 

The reaction of CdCl2 with tV,7V -bis(thiocarbamoyl)hydrazine gave [Cd SC( = NH)NH2 2Cl2] which has been used as a single-source precursor. Upon thermolysis in TOPO at 230 °C it produced CdS particles which showed an absorption edge blue shift of 37 nm in relation to that of the bulk material no chlorine contamination was reported.385... 

Conversion of other heterocyclic systems into pyridazines has also been used, for example the reaction of 3-aminopyrone 9 with hydrazine, followed by oxidative aromatisation <06T9718> and the more unusual utilisation of a 1,2,4-triazole 10 as the source of the N-N unit <06T8966>. In this latter transformation, the intermediate quaternary salt 11 was isolable. An even more unusual example was the reaction of the diazetidine 12 with enolates <06S2885>. 

The irradiation of 5-amino-l,2,4-oxadiazoles 60 in the presence of nucleophilic nitrogen sources (primary amines, ammonia or hydrazine) produced l,2,4-triazolin-5-ones 62, a process which proceeds via cleavage of the N-O bond and addition of the nucleophile to form the intermediate 61 (Scheme 3) <1996JOC8397>. 

Fragments C-N-N-C and S Diazenes and hydrazines with a sulfur source 591... 

Fragments C-N-N-C and S Diazenes and hydrazines with a sulfur source The reaction of 2,3-diazabuta-l,3-dienes with sources of active sulfur to prepare 1,3,4-thiadiazoles has been reviewed in CHEC(1984) <1984CHEC(6)545>, CHEC-II(1996) <1996CHEC-II(4)379> and Chapter 13.12 in the Houben-Weyl Science of Synthesis <2004HOU(13)349>. 

Fuel octane number, 72 392, 395 Fuel oil, as a petroleum product, 78 669 Fuel oil additives amine oxides, 2 473 fatty amines, 2 534 Fuel properties, of ethers, 70 574 Fuel sources, chemical industry, 70 136 Fuel spills, hydrazine, 73 588 Fuels production, hydrocracking for, 76 842-844 Fuel sulfur, 70 54... 

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