2.4- Dinitrophenylhydrazine, structure

Procedures. Chromatographic Purification of Ozonization Products. Ozonization products from ethyl 10-undecenoate and 1-octene were chromatographed on silica gel columns (Baker) and eluted with 15 or 25% ether in petroleum ether (b.p., 30°-60°). Fractions were examined by thin-layer chromatography (TLC) on silica gel G Chroma-gram sheet eluted with 40% ether in petroleum ether. For development of ozonide and peroxide spots, 3% KI in 1% aqueous acetic acid spray was better than iodine. The spots (of iodine) faded, but a permanent record was made by Xerox copying. Color of die spots varied from light brown (ozonide) to purple-brown (hydroperoxide), and the rate of development of this color was related to structure (diperoxide > hydroperoxide > ozonide). 2,4-Dinitrophenylhydrazine spray revealed aldehyde spots and also reacted with ozonides and hydroperoxides. Fractions were evaporated at room temperature or below in a rotary evaporator. 

The sodium bisulfite addition compounds must have a free (or potentially free) ketone-type carbonyl group, since they readily form derivatives with typical ketone reagents such as semicarbazide and 2,4-dinitrophenylhydrazine.174 Decomposition of these derivatives with alkali gives the corresponding adrenochrome derivatives e.g., adrenochrome monosemicarbazone would be obtained from the semicarbazone of the adrenochrome-sodium bisulfite complex.174 If one accepts Tse and Oesterling s formulation of the adrenochrome-sodium bisulfite complex, the semicarbazone would probably have a basically similar structure (i.e. 82). This type of structure is more... 

Given the structure or name of an aldehyde or ketone, write an equation for its reaction with the following nucleophiles alcohol, cyanide ion, Grignard reagent or acetylide, hydroxylamine, hydrazine, phenylhydrazine, 2,4-dinitrophenylhydrazine, primary amine, lithium aluminum hydride, and sodium borohydride. 

Collection of the GC effluent and subsequent MS analysis allowed assignment of a possible molecular formula as Ci9H280. Since boar taint can be eliminated by castration of male pigs, attention was focused on the testosterone and androsterone family of compounds as possible candidates. When the crude volatiles were treated with 2,4-dinitrophenylhydrazine, the boar taint odor was completely removed, implicating a ketone functionality for the lone oxygen atom. Anecdotal information implicated several androstene derivatives, including 47, which was described as having an intense, urine-like odor. 143 An authentic sample of 47 was prepared, and comparison of the GC and MS properties allowed the definitive structural identification of the boar taint compound. 

N , Reactions with. The course of the reaction between diazomethane and hydrazoic acid was studied using N -labeled reactants. It was also found that labeled methyl azide could be reliably analyzed by decompn with HI, and that unambiguously N -labeled niethyl azide could be made by treating methylurea with HN 02 and decompg the product with KOH to CHjNN (Ref 2). Another study noted that in the course of the diazotization of benzhydrazide and 2,4-dinitrophenylhydrazine with HN 02, only azides of the structure R—N=N=N were formed (Ref 1)... 

G with 2,4-dinitrophenylhydrazine (Brady s reagent) and sulfuric acid, a precipitate of compound H (C9H10N4O4) is formed. Propose the structures for compounds E-H. 

Although the target function of neutral CDs is to exert chiral selection in the EKC separation of optical isomers, they have often been used as auxiliary complex ligands as a means of improving resolution of closely eluting achiral positional and structural related compounds or to reduce significantly apparent retention factors. The separation of seven positional and structural naphthalenesulfonate isomers (pH 3.0 phosphate buffer/p-CD) " and five 2,4-dinitrophenylhydrazine (DNPH)-aldehyde derivatives in vehicular emission (pH 9.0 borate buffer/SDS/p-CD) are examples of neutral CD-mediated separations. 

The proton NMR spectrum of a compound of formula CijH 20 follows. This compound reacts with an acidic solution of 2,4-dinitrophenylhydrazine to give a crystalline derivative, but it gives a negative Tollens test. Propose a structure for this compound and give peak assignments to account for the absorptions in the spectrum. 

The structure and composition of obtained compounds were established based on data of element analysis and IR-spectra. For additional identification of ketones V and VII (Scheme 5 and Scheme 7, correspondingly). their interaction with 2,4-dinitrophenylhydrazin were carried out. There were allocated the appropriate hydrazons IX and X (Scheme 9). 

Heating (5)-2-hydroxybutyric acid with methanol and an acid catalyst gives compound E. On reaction of E with lithium aluminium hydride followed by water, compound F is formed which reacts with periodic acid (HIO4) to give G. Finally, on reaction of G with 2,4-dinitrophenylhydrazine (Brady s reagent) and sulfuric acid, a precipitate of compound H (C9H10N4O4) is formed. Propose structures for compounds E-H. 

The combined analytical information suggest that X is butanone. Figure 21,11 shows the correlation between the structure of butanone and the NMR spectrum. The presence of a carbonyl group could be confirmed chemically by reacting X with 2,4 dinitrophenylhydrazine. 

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