Hydrazines 1-alkyl-1-phenyl

Die im Bd. XII/2, S. 805 f., beschriebene Synthese von Thiophosphorsaurc-O-arylester-dihydraziden aus Thiophosphorsaure-dichlorid-O-estern mit Hydrazin bzw. Phenyl-hydrazin kann auf spezielle Phosphorsaure-O-alkyl-dichloridester ubertragen wer-den567 56 9 ... 

When the nitriles were replaced by /V-(ethoxycarbonyl)cyanamide and the products reduced with ethanolic hydrazine hydrate, 2-(iV-ethoxycarbonylureido)-l-alkyl phenyl tellurium compounds were obtained1,2. 

The tclluroxides were not purified. They were reduced by hydrazine hydrate to alkyl phenyl telluriums (page 433). 

When the addition reactions were performed in the presence of (9-ethyl carbamate, 2-(0-elhylcarbamoylamino)-l-alkyl and 2-((9 -ethylcarbamoylamino)-alkyl phenyl tellurium oxides were formed. The tellurium oxides were once again not isolated but reduced with hydrazine hydrate to the corresponding alkyl phenyl telluriums4. 

Ethoxy-phenyl)- X/2, 215 (2-Methoxy-benzyl)- X/2, 47 (4-Methoxy-benzyl)- E16a, 432 (Hydrazin-Alkyl.) 2-(l-Methyl-2-oxo-propyliden)-l-(2-butenyliden)- El4b, 660 (Hydrazon + 2-En-al) (2-Phenoxy-ethyl)- E16a, 427 (N-Alkyl.)... 

Benzyl-1 -(3-hydroxy-propyl)- E16a, 487 (R2N —NO —Red.) 2-(2-Hydroxy-butyl)-l-phenyl- El6a, 601 (R-NH-NH2 + Oxiran) 2-(2-Hydroxy-2-methyl-propyl)- 3 -phenyl- E16a, 601 (R-NH-NH2 + Oxiran) (4-Isopropyloxy-benzyl)- E16a, 432 (Hydrazin-Alkyl.) (4-Propyloxy-benzyl)- E16a, 432 (Hydrazin-Alkyl.)... 

Butyloxy-benzyl)- E16a, 432 (Hydrazin-Alkyl.) [3-(4-Methoxy-phenyl)-l -methyl-propyl]- E16a, 446 (Hydrazon-Red.)... 

The cyclization of ynaminoketones with hydrazine and its alkyl- and phenyl-substituted derivatives has been covered in a number of publications (69HCA2641 76H1921 87ZOR1635). 

Condensation of ethyl acetoacetate with phenyl hydrazine gives the pyrazolone, 58. Methylation by means of methyl iodide affords the prototype of this series, antipyrine (59). Reaction of that compound with nitrous acid gives the product of substitution at the only available position, the nitroso derivative (60) reduction affords another antiinflammatory agent, aminopyrine (61). Reductive alkylation of 61 with acetone in the presence of hydrogen and platinum gives isopyrine (62). Acylation of 61 with the acid chloride from nicotinic acid affords nifenazone (63). Acylation of 61 with 2-chloropropionyl chloride gives the amide, 64 displacement of the halogen with dimethylamine leads to aminopropylon (65). ... 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

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]. 

Diazadiphospholes (182) (R = Me, Ph) are obtained from the condensation of methylene bis(dichlorophosphine) and a hydrazine (Scheme 56) <85AG127>. l-Phenyl-l,2,3,5-diazadiphosphole is a colorless, air-sensitive liquid. It is not alkylated by methyl iodide or trimethyloxonium tetra-... 

Reaction of the 2-acetoxy-3(2//)-furanones (526) with monosubstituted hydrazines gives good yields of the pyridazinium-5-olates (527) together with varying amounts of isomeric products. Alkyl derivatives (527 R = alkyl) have also been prepared by base-catalyzed alkylation (Mel, Me2SO4, PhCH2Cl) of 3-methyl-6-phenyl-5-ethoxycarbonyl-4( 1 //)-pyridazinone. Reduction of the diphenyl compound 527 (R = Ar = Ph) by zinc and hydrochloric acid gives 3-ethoxycarbonyl-5-hydroxy-5-methyl-l,2-diphenyl-2-pyrrolin-4-one (528 R = Ar = Ph) (Scheme 21... 

Catalytic reduction of the 2-nitrophenyIhydrazones (745) and subsequent air oxidation of the tetrahydro-l,2,4-benzotriazines (746) which are formed is used for the synthesis of 3,4-dihydro-1,2,4-benzotriazines (747) (80FES715). In another cyclization of an o-nitro group, which somewhat resembles others (e.g. 736 —> 737) described earlier, treatment of l,l-dialkyl-2-(2-nitrophenyl)hydrazines (748) with acids affords 2-alkyl-1,2,4-benzotriazinium salts (749) (77JCS(P1)478). The 2-nitrophenylbromohydrazone (750) with sodium ethoxide and ethyl cyanoacetate forms 6-bromo-3-phenyl-l,2,4-benzotriazine (751) a mechanism for this interesting transformation, in which the cyanoacetate plays no part, has been proposed (79JHC33). 

I. Sehottle on benzene sulphonate, by A. Seyewetz and L. Poizat on phenyl hydrazine, by E, Fischer on zinc ethyl and magnesium alkyl halides, by F. Ebler and R. L. Krause on metaphosphoric esters and phosphorous esters, by W. Streoker and H. Heuser etc. 

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