Phenylhydrazine, reaction, with

Simple sugars undergo reaction with phenylhydrazine, PhNHNH2, to yield crystalline derivatives called osazones. The reaction is a bit complex, however, as shown by the fact that glucose and fructose yield the same osazone. 

The purity and identity of diethyl chlorothiophosphate prepared by new methods were checked by reaction with phenylhydrazine according to the directions of Mastin, Norman, and Weilmuenster (7). 

Reducing sugars can be detected by reaction with phenylhydrazine to yield a hydrazone product, except the result of the reaction is not what one might imagine giving the structure of aldoses and ketoses. Glucose, for example, can react with phenylhydrazine to yield the anticipated... 

The amino pyrrole 29 derived from the reaction with phenylhydrazine <1998JOC9131> was found to undergo an acid-catalyzed intramolecular condensation with the carbonyl present to give the 3//-pyrrolo[l,2-A pyrazole 30 ring system in a good yield (75%) (Equation 2). 

The intermediacy of phenylhydrazones 369 (R = H = Me) is suggested in the transformation of some 2-alkylindoles into the corresponding pyrazoles 370 by the reaction with phenylhydrazine hydrochloride in refluxing acetic-hydrochloric acid (Scheme 58) (76CJC1020). Here, after preliminary acetylation at C(3) of the indole by the acetic-hydrochloric... 

Carboxy-2-pyridylthio)propionic acids, prepared by the reaction of 2-mercatopyridin-3-carboxylic acid with 3-bromopropionic acid in aqueous KOH, undergo cyclization upon treatment with anhydrous sodium acetate and acetic anhydride to afford 2,3-dihydrothiopyrano[2,3-3]pyridin-4(4//)-ones. These products undergo further reaction with phenylhydrazine to give the phenylhydrazone (isolated) and then Fischer indole cyclization to give novel 5/7,1177-pyrido[2, 3 2,3]thiopyrano[4,3-3]indoles <2000JHC379>. 

Poly(chalcones) (183), which themselves are the products of Knoevenagel condensation of aromatic dialdehydes and diacetyl compounds, have been transformed into polylpyrazo-lines) (185) by reaction with phenylhydrazine (184) (72MI11107). The reaction (Scheme 88) was conveniently conducted in excess phenylhydrazine and yielded polymers which were described as being brilliantly fluorescent in solution. The poly(pyrazolines) (185) exhibited glass transition temperatures between 150 and 210 °C and were stable, in some cases, up to 630 °C. 

Different results, depending on the structure of the initial 2-benzopyry-lium salt, were obtained also in reactions with phenylhydrazine. Thus, the 1,3-dimethyl-substituted cation 35 is converted into an isoquinolinium salt 174(R = Ph)(70KGS1308), whereas the 1,3-diphenyl derivative 178 forms an indole 180 via the bishydrazone 179 by the Fischer reaction (71CB2984). 

The structure of this sugar was established as follows (a) reaction with phenylhydrazine yielded 4-methyl-D-glucosazone 11 (b) oxidation (HOBr) yielded a methylmannonolactone, which exhibited the properties that are characteristic of 8-lactones.7... 

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