Hydrazine yield

Reaction of an acid chloride with trimethylsilylacetylene produces an a,P-ethynyl ketone, which on treatment with substituted hydrazines yields a mixture of 1,5- and 1,3-substituted pyrazoles (34). The ratio is dependent on the reaction conditions (eq. 3). 

Rotation around the NN bond in hydrazine yields three staggered conformers, one in whieh the lone pairs are anti and the other two (equivalent struetures) in which they are gauche. 

Cyclization of 6-diethylaminohex-3-en-5-yn-2-one (375), an ynaminoketone vinylog, with hydrazine yields 3-diethylamino-7-methyl-5//-l,2-diazepine (375) (97DIS). 

Finally the aminoquinoline bearing a primary amine at the terminal carbon atom of the side chain is itself an effective antimalarial drug. Ring opening of 2-methyltetrahydrofuran by bromine gives the dibromide, 99. The primary halide is sufficiently less hindered so that reaction with potassium phthalimide affords exclusively the product of displacement of that halogen (100). Alkylation of the aminoquinoline with lOO affords the secondary amine, 101. Removal of the phthalimide group by means of hydrazine yields primaquine (102). ... 

Lustrous yel needles, mp 33° (Refs 2 3), prepd by the action of hydroxylamine (yield 50%), hydrazine (yield 20%), or Na azide on 2-naphtha-lenediazonium sulfate (Ref 3) or by the action of hydroxylamine sulfate on 2-naphthalene diazonium sulfate in sulfuric acid/glac acet ac (Ref 5)... 

The oxazolotriazinone 88 undergoes ring transformation when treated with ammonia or with primary amines to give imidazo[l,2-f>][l,2,4]triazines 89. SimUar treatment with hydrazine yields triazino[4,3-ft][l,2,4]triazines 90 <95MI07 96CA(125)202176>. 

Disubstituted tetrazoles are conveniently prepared from acyl hydrazines (98) and diazonium salts.166 The reaction proceeds through the intermediate tetrazenes (99) followed by cyclization to the tetrazole (100) (Scheme 13). The intermediate can be isolated under mildly basic conditions. Symmetrically 1,2-diacylated hydrazines yield 1-substituted tetrazoles through the elimination of one of the acyl groups.166 - 168 Diformyl-hydrazine is a very convenient starting material for 1-substituted tetrazoles.166, Unsymmetrically 1,2-diacylated hydrazine usually results in mixtures.169... 

Diazotization of 3-(4-aminophenyl)sydnones followed by reaction with 1- or 2-hydroxynaphthalene provides azo dyestuff materials <1998MI209>. A new type of reaction between 4-acetyl-3-arylsydnones and hydrazine yields substituted pyrrolidinones by a cycloaddition process involving loss of nitric oxide (Equation 20) <1999H(51)95, 2001AHC73>. 

Basic solid liquid two-phase conditions with f-butyl peroxide and N-benzylquininium chloride convert cyclohex-2-enone preferentially into the 2(S),3(S)-oxirane (20% ee) which, upon purification and treatment with hydrazine, yields (S)-cyclohex-2-enol [7]. This reaction contrasts with the direct reduction of cyclohex-2-enone to the /J-isomer by lithium aluminium hydride in the presence of quinine [20]. 

Complex 61 is also accessible from the 2-nitrophenyl isocyanide complex 68 by reduction of the nitro group with Sn/HCl. Incomplete reduction of the nitro group in 68 with Raney-Nickel/hydrazine yields, after intramolecular cyclization, the complex 70 with the NH,NOH-stabilized benzimidazolin-2-ylidene ligand. Complex 69 with the 2-hydoxylamin-substituted phenyl isocyanide ligand presumably occurs as an intermediate in this reaction. The alkylation of both the NH,NH- and the NH, NOH-stabilized NHC ligands in 67 and 70, respectively, proceeds readily (Fig. 23) [184, 185]. 

In the reaction of l-hydroxy-2-oxo-l-cyclohexanecarboxamide and cyan-amide, the 2-aminooxazole 282 was formed. Treatment of 282 with hydrazine yielded the semicarbazide 283, which on iodine oxidation gave the perhydro-2,4-quinazolinedione 284 (87JPR177). Although the configuration of the product was not given, the cis annelation can be deduced from the published NMR data. 

Refluxing an aqueous solution of urea and hydrazine yields hydrazodicarbox-amide, H2NC(=0)NHNHC(=0)NH2 [110-21-4], which on chlorination yields azodicarbonamide H2NC(=0)N=NC(=0)NH2, used as a blowing agent for polymers ... 

The diphenyl derivative 388, R = R = Ph, has an absorption band at 1495 cm S which has been assigned to the carbonyl group. This assignment could be questioned. The following chemical reactions of the compound 388, R = R = Ph, may be noted (a) Raney nickel desulfurization followed by oxidation with manganese dioxide yields dibenzyl ketone,(b) hydrazine yields 3,5-diphenyl-4-hydroxypyrazole (390), (c) phenylhydrazine yields PhCH2COCPh=NNHPh," (d)... 

Reaction of 2-amino-3-bromoprop-l-ene-l,l,3-tricarbonitrile 284, easily accessible from the bromination of the dimer of malononitrile, with hydrazine or phenyl hydrazine yielded 1,4-dihydropyridazines 285 and 286, respectively (Scheme 70) <2003HAC612>. 

Pyridine reacts with sodium hydrazide in the presence of hydrazine to yield 2-hydrazinopyridine in the absence of free hydrazine a hydrazo compound is formed (Scheme 88) (64AG(E)342). A difference between hydrazination and amination is the formation of 1,4-adducts which cannot be rearomatized even on heating. This is reflected in the behaviour of quinoline, which gives only a 0.5% yield of a -hydrazino product, whereas 4-methylquino-line is hydrazinated in 76% yield (64AG(E)342). Acridine behaves differently with sodium hydrazide/hydrazine, 9,10-dihydroacridine is formed almost quantitatively, but reaction in the absence of hydrazine yields 9-aminoacridine (65%). An even higher yield of 9-amino-acridine is obtained when sodium Af.AC-dimethylhydrazide is used (Scheme 89). Good evidence for intermediacy of (151) comes from the isolation of (152) on hydrolysis of (151). 

Reaction of diisocyanates with hydrazine yields polysemicarbazides [43,44]. 

The reaction of zirconium(IV) fluoride with excess anhydrous hydrazine yields the 1 2 adduct ZrF4(N2H )2, which loses one molecule of hydrazine at 230-245 °C. ZrF4(N2H4)2 and ZrF4(N2H4) have been characterized by their IR spectra.55... 

Sulphur dioxide, when slowly passed into a cooled alcoholic solution of hydrazine, yields the hydrazine salt of hydrazine disulphinic acid, N2H2(S02.N2Hs)2.° When the gas is passed into an aqueous solution of hydrazine hydrate, hydrazine pyrosulphite, (N2H4)2. H2S205, is formed, which, on neutralisation with hydrazine hydrate, yields hydrazine sulphite, (N2H4)2.H2S03. ... 

Condensation of 2-chloro-3-cyanopyridines 6 (X = Cl) with hydrazines yields 3-aminopyrazolo[3,4-fe]pyridines 7. The majority of workers9-15 report 1 -H derivatives but 1-substituted compounds have also been prepared.9,16 17 In one instance9 a hydrazinopyridine (6 R2 = H, R3 = CN,... 

Nitroguanidine, warmed with an aqueous solution of hydrazine, yields N-amino,N -nitroguanidine,15 white crystals from water, m. p. 182°. This substance explodes on an iron anvil if struck with a heavy sledge hammer allowed to drop through a distance of about 8 inches. It may perhaps have some interest as an explosive. 

If primary or secondary amines are used, AT-substituted amides are formed. This reaction is called aminolysis. Hydrazines yield the corresponding hydrazides, which can then be treated with nitrous acid to form the azides used in the Curtius rearrangement. Hydroxyl amines give hydroxamic acids. 

The treatment of the 2C-B phthalimide described above, with cuprous cyanide rather than cuprous chloride, gave rise to the cyano analog which, on hydrolysis with hydrazine, yielded 2,5-dimethoxy-4-cyanophenethylamine (2C-CN). Hydrolysis of this with hot, strong base gave the corresponding acid, 2,5-dimethoxy-4-carboxyphenethylamine, 2C-COOH. No evaluation of either of these compounds has been made in the human animal, as far as I know. 

A new synthesis of pyrroles generates a 1,3-diketone by reacting a lithium enolate of a ketone with an acid chloride in situ addition of a hydrazine yields, potentially, a tetrasubstituted pyrazole.297 Tolerant of a wide range of functional groups, it is also easily adapted to rapid preparation of fused bicyclic pyrazole systems. 

This reaction appears to be similar to the imidazo-pyridine formation mentioned above, most likely via a [5+1] insertion reaction of the isocyanide into the corresponding hydrazone. This reaction mechanism seems likely since only electron-rich aromatic hydrazines yielded cinnolines. The Ugi 4-CR reaction with phe-nylhydrazine is known and has been reported to give the expected Ugi-type 4-CR product. 

As Intermediates in Ammonia or Hydrazine Yielding Reactions of N2 Complexes... 

The racemic acid 399 was treated with oxalyl chloride to afford an acyl chloride 401, which on reaction with anhydrous hydrazine yielded the hydra-zide 402. The latter was converted to the azide 403 by treatment with nitrous acid. Photolysis of 403 which a high-pressure mercury lamp afforded the lactam 404. This lactam was synthesized earlier by Japanese chemists by an entirely different method (187). 

Hydroxycoumarins can be converted into 4-arylcoumarins via the Pd-catalysed coupling of 4-stannylcoumarins with aryl iodides (95SC2883), whilst the three component reaction of 4-hydroxy-coumarins, triethyl orthoformate and hydrazines yields A-derivatives of 3-methylenechroman-2,4-diones (95M579). 

The reactions of tropone with hydroxylamine or hydrazine yield 2-aminotropone (59MI1, p. 415), in the first case admixed with troponeoxime (Section IV,A,8,b). Besides nucleophilic substitution, an additive mechanism was discussed (66MI2, p. 135 73CRV293, p. 354). 

Treatment of dehydro-L-ascorbic acid (72) with phenyl hydrazine followed by hydroxylamine yielded the hydrazone oxime (73a), cyclization of which in refluxing acetic anhydride gave 4-[l-//u< o-2,3-diacetoxy-(l-hydroxypropyl)]-2-phenyl-l,2,3-triazole-5-carboxylic acid lactone (74a) <77CAR(59)141>. Analogous reactions of the derivatives (72) with substituted aryl hydrazines yielded the triazoles (74b-d). Alternatively, the hydrazone oximes (73a-d) may be treated with HBr in... 

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