Hydrazine substituted aryl derivs

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... 

Recyclization can also take place with a change in the ring size. Thus, 3(5)-methyl-5(3)-(2-hydroxyphenyl)-4-nitropyrazole is obtained with a high yield in the reaction of 2-methyl-3-nitrochromone with hydrazine [543, 544], Instead of hydrazine it is possible to use its alkyl or aryl derivatives. In this case 1-substituted 4-nitropyrazoles are isolated [543, 545] (Scheme 96). 

The halogenopurines react with many other nucleophiles including hydrazines, hydrox-ylamine and alkoxyamines, sulfonic acids and thiocyanates, and compounds with active methylene groups such as diethyl malonate furnish appropriate purine derivatives which offer valuable routes to alkyl and substituted alkyl derivatives. Also aryl groups have been substituted for halogen using aryllithiums (63N224). 

Many (benzo)pyridazines are made from 1,4-diketo compounds, and the industrial supply of, for example, maleic and phthalic anhydrides and mucohalic acids make them attractive and widely used starting materials, which can be used in conjunction with substituted hydrazines to give a range of A-substituted derivatives. Some other 1,4-diketo compounds are commercially available on a smaller scale, including, for example, certain 3-benzoylpropionic acids from which 6-aryl-4,5-dihydro-3(2//)-pyridazinones can be prepared. When such precursors are not commercially available then ease and scope of synthetic approaches to the starting materials must be considered, but for established routes, such as 6-aryl-4,5-dihydro-3(2//)-pyridazinones from 3-aroylpropionic acids, a variety of synthetic methods have been developed so that a wide range of (substituted)aroyl derivatives can be prepared. Synthetically useful preformed (benzo)pyridazine derivatives that are commercially available include 4,5-dichloro-3(2F/)-pyridazinone, 3,6-dichloropyridazine, and 1,4-dichlorophthalazine. 

Levenberg, B. Isolation and Structure of Agaritine, a y-Glutamyl-substituted Aryl-hydrazine Derivative from Agaricaceae. J. Biol. Chem. 239, 2267 (1964). 

Chaskar et al. (2010) developed a simple, efficient, and environmentally friendly method for the synthesis of substituted indole derivatives using aryl hydrazines and... 

In a similar manner, phthalazine or its alkyl- or aryl-substituted derivatives are obtainable from 1,2-diacylarenes (Scheme 76). Phthalaldehydic acid and its analogs are transformed by hydrazines into the corresponding phthalazin-l(2//)-ones. Phthalazin-l(2iT)-one itself is prepared from naphthalene by oxidation, subsequent treatment with hydrazine and decarboxylation as shown in Scheme 77 (55YZ1423,64FRP1335759). 4-Substituted phthalazin-l(2iT)-ones are prepared in a similar way from 2-acylbenzoic acids. 3-Hydroxyphthalides,... 

In the case of the 3-methylsulfanotriazine derivative 198, a simple treatment with arylhydrazides allowed the ring closure to the 3-aryl-substituted products 199 <2003KGS950>. In other cases, the hydrazine function was first introduced to position 3 of the [l,2,4]triazine ring and these compounds were then cyclized by using various reagents. 

Although 3-aminoquinazoline derivatives are normally prepared de novo from hydrazine starting materials, they can also be prepared by N-amination reactions. Thus, treatment of l-substituted-2,4(177,377)-quinazolinediones 32 with 0-aryl hydroxylamines under basic conditions gives 3-amino-l-substituted-2,4(177,377)-quinazolinediones 33 which are intermediates in the synthesis of 3-amino-2,4(l/7,3/7)-quinazolinedione antibacterial agents <20020PD230, 2005JHC669, 2006JME6435>. 

Similar results were reported on reacting Af aryl-substituted 256 with hydrazine. Reacting an aryl 256 derivative with hydroxylamine hydrochloride gives 262 (Equation 33) <2002JHC869>. 

Examples of semicarhazides prepared from alkyl- or aryl-substituted hydrazines are shown in Table IV, and of the reaction of hydrazine derivatives with HOCN or HSCN in Table V. 

The lower members of the homologous series of 1. Alcohols 2. Aldehydes 3. Ketones 4. Acids 5. Esters 6. Phenols 7. Anhydrides 8. Amines 9. Nitriles 10. Polyhydroxy phenols 1. Polybasic acids and hydro-oxy acids. 2. Glycols, poly-hydric alcohols, polyhydroxy aldehydes and ketones (sugars) 3. Some amides, ammo acids, di-and polyamino compounds, amino alcohols 4. Sulphonic acids 5. Sulphinic acids 6. Salts 1. Acids 2. Phenols 3. Imides 4. Some primary and secondary nitro compounds oximes 5. Mercaptans and thiophenols 6. Sulphonic acids, sulphinic acids, sulphuric acids, and sul-phonamides 7. Some diketones and (3-keto esters 1. Primary amines 2. Secondary aliphatic and aryl-alkyl amines 3. Aliphatic and some aryl-alkyl tertiary amines 4. Hydrazines 1. Unsaturated hydrocarbons 2. Some poly-alkylated aromatic hydrocarbons 3. Alcohols 4. Aldehydes 5. Ketones 6. Esters 7. Anhydrides 8. Ethers and acetals 9. Lactones 10. Acyl halides 1. Saturated aliphatic hydrocarbons Cyclic paraffin hydrocarbons 3. Aromatic hydrocarbons 4. Halogen derivatives of 1, 2 and 3 5. Diaryl ethers 1. Nitro compounds (tertiary) 2. Amides and derivatives of aldehydes and ketones 3. Nitriles 4. Negatively substituted amines 5. Nitroso, azo, hy-drazo, and other intermediate reduction products of nitro com-pounds 6. Sulphones, sul-phonamides of secondary amines, sulphides, sulphates and other Sulphur compounds... 

This microwave-accelerated double alkylation reaction was applicable to a variety of aniline derivatives and dihalides, furnishing N-aryl azacycloalkanes in good to excellent yields [89]. The reaction was applicable to alkyl chlorides, bromides and iodides and was extended to include hydrazines [90]. This improved synthetic methodology provided a simple and straightforward one-pot approach to the synthesis of a variety of heterocycles such as substituted azetidines, pyrrolidines, piperidines, azepanes, N-substituted-2,3-dihydro-Iff-isoindoles, 4,5-dihydro-pyrazoles, pyrazolidines, and 1,2-dihydro-phthalazines [91]. The mild reaction conditions tolerated a variety of functional groups such as hydroxyls, carbonyls, and esters. 

Practically all linear 1,3-diketones13 7-142 give the corresponding pyrazoles with hydrazine104 143 and its derivatives.144-149 The reaction of aliphatic diketones should be moderated by dilution, cooling, or the addition of acid.137 Since pyrazole rings are stable, severe conditions may be used in their preparation where necessary. For details of the hydrazine/acetylacetone reaction see Wiley and Hexner.150 Evidently the reaction proceeds via the formation of the monohydrazone (11)151 which, when aryl-substituted, is less reactive and may be isolated.83,152-159 (However, see reference 159a.) It is not known if the monohydrazones are cyclic (12) or not, but they are... 

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