Hydrazine substituted derivs

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,... 

Phthalic anhydride and diethyl phthalate are easily converted with hydrazine into 4-hydroxyphthalazin-l(2/f)-one. Its substituted derivatives have been prepared using substituted hydrazines, substituted phthalic anhydrides, or diesters or disodium salts of substituted phthalic acids (Scheme 81). However, condensation of phenylhydrazine with phthalic anhydride gives only a small amount of the corresponding phthalazine, the main product being 2-anilinophthalimide. This can be rearranged in the presence of base into the phthalazine derivative. For the preparation of 2,3-disubstituted derivatives, 1,2-disub-stituted hydrazines are reacted with the appropriate phthalic anhydrides or phthaloyl chlorides. Derivatives of 4-amino- or 4-hydrazino-phthalazin-l(2iT)-one have been prepared either from the corresponding monothiophthalimide and 3-aminoisoindolin-3-one (1S4) or from ethyl 2-cyanobenzoate (155) and hydrazine hydrate (Scheme 82). Similarly,... 

Treatment of cotarnine and similar compounds with hydrogen cyanide, alkoxides, mercaptides, hydroxylamine, hydrazine, and amines has been reported to give 1-substituted derivatives of 1,2,3-tetrahydroisoquinoline (171, R = CN, OR, SP, NHOH, NHNH, NHR) (262-265). 

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

Hydrazine or its substituted derivatives react with biphenyl-2,2 -dicarboxylic anhydride (1) to provide 1,2-diazocinedione derivatives 2.13 1S... 

Hydroquinone is another safe alternative to hydrazine and was originally covered under a Betz patent. Related compounds and their alkyl-substituted derivatives were similarly patented, including o- and /7-diamino and aminohydroxybenzenes. 

The enamine 141 can be cyclized to the [l,2,4]triazolopyridopyrimidine 142 upon treatment with sodium ethoxide (Scheme 40) <2002M1297>. This fused tricyclic system may also be obtained, like the pteridine analogue (cf. Scheme 38), from the reaction of hydrazonoyl halides and pyridopyrimidines such as 143, and also by treatment of the triazolopyrimidine 144 with dimethylformamide dimethylacetal (DMF-DMA) dimethylacetal and subsequent ring closure <2003MOL333, 2003HAC491> (Scheme 41). Another series of triazolopyridopyrimidines, for example, 146, can be prepared from a hydrazine-substituted pyridopyrimidine 145, in two ways either directly by reaction with an acid chloride, or via a derived hydrazone (Scheme 42) <1996MI585>. 

Cyclocondensation of 2-aroylbenzoic acid 223 with hydrazine gave the phthalazine derivative 224, which was alkylated with ethyl chloroacetate in aqueous sodium hydroxide or pyridine to give the N-substituted derivative 225. Condensation of the latter with hydrazine afforded the hydra-zide 226, which could be cyclized to give the 2//[l,2,4]triazino[3,4-a]phthalazin-3(4tf)-one 227 (91MI3). 

Thiadiazole 57 reacts with cyclic secondary amines such as piperidine, piperazine, and morpholine to afford the substituted derivatives 64 in 80-85% yield (Equation 13) <2005EJM1346>. Under similar conditions, thiadiazole 57 reacts with hydrazine hydrate to give the thiadiazolhydrazine 65 in 97% yield <2004BML5967>. 

Types of compounds are arranged according to the following system hydrocarbons and basic heterocycles hydroxy compounds and their ethers mercapto compounds, sulfides, disulfides, sulfoxides and sulfones, sulfenic, sulfinic and sulfonic acids and their derivatives amines, hydroxylamines, hydrazines, hydrazo and azo compounds carbonyl compounds and their functional derivatives carboxylic acids and their functional derivatives and organometallics. In each chapter, halogen, nitroso, nitro, diazo and azido compounds follow the parent compounds as their substitution derivatives. More detail is indicated in the table of contents. In polyfunctional derivatives reduction of a particular function is mentioned in the place of the highest functionality. Reduction of acrylic acid, for example, is described in the chapter on acids rather than functionalized ethylene, and reduction of ethyl acetoacetate is discussed in the chapter on esters rather than in the chapter on ketones. 

Corresponding 4-diethylamino-substituted derivatives are formed by the reaction of 5,Af-diethyl-(iV -chlorosulfonyl) chloroformamidine (35) with hydrazines <85M1321> (Equation (9)). 

Displacement of the methylthio group in thiopyrano[2,3-,7 pyrimidine 219 with pyrrolidine, morpholine, and hydrazine gave the 2-substituted derivatives 220. Diazotization of 219 with NaN02 in AcOH followed by hydrolysis of the resulting diazonium salt gave the acetyl derivative 221 <1977JHC361>. 

The reaction of a pyridazine, 5 dicarboxylic acid derivative with hydrazine remains a favored approach for the preparation of pyridazino[4,5-4 pyridazines <2000TL2863, 2002JCCS217>, and di- /t-butyl hydrazodicarboxylate has been used as a hydrazine substitute in the presence of perhydro derivatives, as illustrated in Equation (6) <1993JPC13408>. 

Preparation of silyl-substituted semicarbazides from the reaction of trimethylsilyl isocyanate and hydrazine or derivatives [92]. 

Substituted hydrazine or derivative Reagents Semicarbazide, thiosemicarbazide, or semicarbazone Ref. 

Recent work describes the addition reactions of hydrazine and substituted derivatives to NP (62). The kinetic studies were done using UV-Vis absorption and mass spectrometric methods. Different stoichiometries were found, depending on the nucleophile. We can distinguish three different mechanistic paths, and these will be successively presented, with an effort to extract some common mechanistic features. 

We refer to the original work (62) in order to further analyze the above results. Summarizing, the key mechanistic requirements in the addition behavior of hydrazine and its substituted derivatives are the presence of two protons in an adjacent position to the reacting N atom for the evolution of fast addition processes leading to cleavage... 

A similar series of nucleophilic substitutions has been performed on 4-chloro[l,2,3]triazolo[4,5-c]pyridine (246) and some of its simple substituted derivatives. On compound 246 itself formic acid gives the triazolo-pyridin-4-one,192 ammonia gives the 4-amino compound,192 and hydrazine the 4-hydrazino derivative 245 hydrosulfide gives the 4-thione192 and thiourea in propanol, at first reported151 to give the 4-thione, has subsequently been... 

Substituted hydrazines provide 1- and/or 2-substituted derivatives depending on the nature of 125. Thus the dione 125 (X = C02Et, R = =0) and phenylhydrazine gave a mixture of isomers 126a and 126b (R1 or... 

Recyclisation Reactions of Heterocyclic Compounds Involving Hydrazine and Its Substituted Derivatives O. P. Shvaika and V. N. Artemov, Russ. Chem. Rev. (Engl. Transi.), 1972, 41, 833-849. 

Cyano-3-methyl-5,6-dihydro-l//-pyrido[l,2-a]quinazoline-l,6-dione and its 5-substituted derivatives were prepared from 2-cyano-3-methylpyrido[l,2-a][3,l]benzoxazin-6-one with ammonium acetate at 200°C for 4 h, with hy-droxylamine hydrochloride and (thio)ureas in a boiling mixture of pyridine and ethanol for 4-7 h, with hydrazine hydrate, phenylhydrazide, primary aliphatic and (hetero)aromatic amines in boiling ethanol for 3-6 h (93CCC1953). 

In 1958, Ikekawa10 synthesized 2,7-naphthyridine and various substituted derivatives. His approach involved the reaction of 4-methylnicotinic acid with formaldehyde to afford the lactone 99 (R = H). The reaction of 99 with ammonia in methanol yields the amide (100) which, on oxidation with chromium trioxide, afforded 2,7-naphthyridin-l-one (101). This substance was converted into 2,7-naphthyridine (102, R = H) by consecutive treatment with phosphorus oxychloride, hydrazine, and copper sulfate. The 3-methyl derivative was similarly prepared starting with acetaldehyde. 

Aminobenzo[6]thiophene and its simple ring-substituted derivatives are most conveniently obtained by reduction of the corresponding nitro compound with tin and hydrochloric acid,883,334,544,545 iron and hydrochloric acid,555 ferrous sulfate and ammonia,185,330 333 334,497 sodium borohydride and palladized charcoal,337 cata-lytically,152, 422,488,543 or, preferably, with Raney nickel and hydrazine hydrate.152,298,338,497,556 Several 5-aminobenzo-[6]thiophenes may also be made by cyclization reactions (Section IV, D).239,330,331 333,494... 

A novel synthesis of aza-/Mactams (Scheme 7.14) from the adducts of the reactions with N-Boc hydrazines 103 was recently reported by Naskar [53]. Thus, direct cyclization of 106 [52] with DIC gave 107, while participation in the Ugi reaction upon the addition of an aldehyde 109 and an isocyanide 110 gave more substituted derivatives 111 [53]. 

---