Sulfuric acid hydrazine derivatives

Amino-4-nitropheno1 is produced commercially by the partial reduction of 2,4-dinitrophenol This reduction may be achieved electrolyticaHy using vanadium (159) or chemically with polysulftde, sodium hydrosulftde, or hydrazine and copper (160). Alternatively, 2-acetamidophenol or 2-methylbenzoxazole may be nitrated in sulfuric acid to yield a mixture of 4- and 5-nitro derivatives that are then separated and hydrolyzed with sodium hydroxide (161). 

The 1,5-Bis (o ), mp 209 (m.-), mp 244°, and (p-), mp 262° derivs were prepd by Braun Rudolph (Ref 2) by nitrating the parent compd with a l/l mist of fuming nitric acid + sulfuric acid on a water bath. Horwitz Gra-kauskas (Ref 4) prepd the l,5-Bis(p-dinitro) deriv by coupling diazotized p-nitroaniline with 1-acetyl-2-(4,-bromo benzoyl) hydrazine, separating the tetrazole following cyclization l-(m-Nitrophenyl)-5-(p-nitrophenyl)-tetrazole, crysts, mp 170° (Ref 2)... 

The results of nitration reactions depend on reagents and the acidity of the medium. Thus fuming nitric acid in concentrated sulfuric acid converts (410a) to the 3-nitro derivative while with acetyl nitrate reaction occurs exclusively at C-4 (equation 50). The nitration in the 4-position can also conveniently be done with nitronium tetrafluoroborate. The reduction of these nitro compounds by hydrazine in the presence of palladium on charcoal provides a versatile route to 4-amino-7,6-borazarothieno[3,2-c]pyridines (75ACS(B)46l>. In the nitration of 4,5-borazarothieno[2,3-c]pyridines (e.g. 409a), peri effects from the substituents on the boron atom lead to formation of a considerable amount of the 2-nitro derivatives. 

As an eflFective ketone, DHA reacts readily with hydrazines to form a variety of 2- and 2,3-hydrazones. These reactions are characteristic of the 2,3-bisketobutyrolactone group. The standard assay of AA takes advantage of the reaction between DNPH and DHA to give a bishydra-zone that exhibits a distinctive absorption band at 516 nm in dilute sulfuric acid solution (17). This reaction is not quantitative a mixture of the hydrazone and decomposition products is formed. We have estimated that the derivative is formed in about 35% yield. The success of the DNPH reaction as a quantitative assay for AA is dependent on the use of adequate controls, representing a significant weakness of the method. 

Hurst <93AHC(58)215> has summarized the results of nitration of 1-phenyl-A -pyrazolines for instance, l,5-diphenyl-3-aryl-2-pyrazolines are nitrated by potassium nitrate in sulfuric acid to afford the 1-p-nitrophenyl derivative in quantitative yield. Thermal ring opening of A -pyrazolin-3-carboxylic acids has been used as a method of preparation of )8-aminonitriles <94T7543>, while base-promoted ring opening of 1,1 -disubstituted-3-amino-A -pyrazolinium salts affords either N,N-disubstituted hydrazines or a,)S-unsaturated amidrazones <86SC585>. 

During the polymerization of aromatic diacids and diesters with hydrazine in fuming sulfuric acid, aromatic oxadiazole units are formed first which are subsequently methylated by monomethyl sulfate or its homologues (derived from reaction of the diester with H2SO4) forming an aromatic N-methyl oxadiazolium polymer. This polymer is hydrolyzed during the spinning operation to the fiber polymer, i.e., p-/m-phenylene oxadiazole/N-methyl hydrazide copolymer. 

Aldehyde (46) has also been converted into diazole-fused thiophenes. Reaction with hydrazine derivatives gave hydrazones (50), which on treatment with acid were converted to diazoles (51). Unfortunately, the nitrogen substituent was sometimes scrambled, leading to mixtures of (51) and (52). The final sulfur oxidation was uniformly high yielding [28,29] (Scheme 6.13, Table 6.3). 

Hydroformylation can be incorporated efficiently into tandem reactions [17]. Various tryptamine-based pharmaceuticals were prepared by hydroformylation carried out in the presence of hydrazine derivatives. The aldehydes were generated in situ from the alkenes and trapped by the hydrazines to form the hydrazones that on cyclization gave the indole products. Application of water-soluble ligands such as TPPTS made it possible to execute hydroformylation and cyclization in one step in aqueous sulfuric acid [18]. 

Primary alcohols can be identified by oxidizing them to aldehydes with chromic acid or potassium permanganate in the presence of 2 n sulfuric acid. The aldehyde formed can be isolated by distillation and identified in the form of its dimedone derivative (see p. 230). Primary alcohols can be identified in this manner in the presence of secondary and tertiary alcohols, because dimedone condenses only with aldehydes, i.e., with products of a mild oxidation of primary alcohols. Carbonyl compounds can be isolated from an aqueous distillate by precipitating them with 2,4-dinitrophenyl-hydrazine (see p. 218). If paper chromatography cannot be used for identification (see p. 222), it is advisable to oxidize at least 500 mg of alcohol. 

Derivatives of ketones and aromatic and unsaturated aldehydes are most easily hydrolyzed. In the case of aliphatic aldehydes the cleavage does not take place so easily. Of course, the substituents of the used hydrazine also play a role. For example, semicarbazones are hydrolyzed with difficulty differences in the reactivity of semicarbazones were successfully applied for the separation of a mixture of a- and ) -citral. For the separation of hydrazones of a-, J -unsaturated aldehydes, oxalic or phthalic acid can be used for easily hydrolyzable oximes, sulfurous acid may serve. More stable hydrazones require mineral acids for their hydrolysis, often concentrated, and also elevated temperatures (79). It is advantageous to carry out the cleavage in an inert atmosphere to prevent unwanted side reactions (80). 

See Hydrazine and derivatives, above Hydrogen sulfide Oxidants Non-metal hydrides, above Potassium phosphinate Air, or Nitric acid Sulfur dioxide, below... 

A variety of miscellaneous derivatives of gulonolactone has been reported. Linn treated D-glucofuranurono-6,3-lactone (7) with chlorobenzene and aluminum trichloride in order to obtain115 6-deoxy-6,6-diphenyl-L-gulonic acid (70). Various related compounds were also prepared. When 7 was treated with sulfur dioxide and 2-(isonicotin-oyl)hydrazine in water, 6-deoxy-6-(2-isonicotinoylhydrazino)-6-sulfo-D-gulono-1,4-lactone (71) was formed in 81% yield.116,117 Kawabata... 

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