Benzylidene phenylhydrazone

Pyrrolo annulated triazine 77 was prepared (88TL4415) by the [6 + 4]-cycloaddition of azoniafulvene ion 76 with azomethine imines generated from benzylidene phenylhydrazone (Scheme 19). 

Both L-gulose12,13 (9) and D-gulose (d-9, see Ref. 10) have been oxidized with bromine to L- or D-gulonic acid, respectively (see Scheme 1). L-Gulose (9) has been prepared by a number of different procedures. Schemes 2 and 3 show two early procedures that afforded L-gu-lose, but the overall yields were low (<30%). In the first procedure12 (see Scheme 2), D-glucitol (10) was converted into 2,4-O-benzylidene-D-glucitol (11), which was then oxidized with lead tetraacetate to 2,4-O-benzylidene-L-xylose (12). Nitromethane was added to 12 to afford crystalline 13 in 50% yield. Hydrolysis of 13 provided 14, which was treated with sodium hydroxide, followed by sulfuric acid, to afford 9, which was isolated in 52% yield as the 2-benzyl-2-phenylhydrazone. 

Benzaldehydepherrylbydrazone (called Benzyliden -phenylhydrazin Benzal-phenyl-hydraZin or Benz-aldehyd-phenylhydrazon in Ger), C6H6.NH.N CH.C6Hs, mw 196.24, N 14.28%, is described in Beil 15,134,(31) St [57]... 

Anodic oxidation of substituted hydrazones may induce ring closure. Oxidation of /7flrfl-substituted phenylhydrazones of 2-oxophenylacetonitrile yields derivatives of 1-phenyl-3-cyano-l/7-indazoles [73] p-nitrobenzylidene-o-phenylenediamine is oxidized in MeCN-LiC104 to 2-(pnitrophenyl)benzimidazole [74], chalchone phenylhydrazone in MeCN-C5H5N-LiC104 to 1,3,5-triphenylpyrazol [74], and benzylidene 2-pyridylhydra-zone (XXIV) to 3-phenyl-j -triazolo[4,3-a]pyridine (XXV) oxazoles and imidazoles may be prepared similarly [74] ... 

Phenylhydrazone Benzylidene deriv. 2-Acetyl-3-methyl-7-nitro 2-Acetyl-3-methyl Phenylhydrazone 2,4rDinitrophenylhydrazone Oxime... 

Methyl 4,6-0-benzylidene-3-deoxy-3-phenylazo- -D-glucoside allowed to react with Na-methoxide in methanol -> phenylhydrazone. Y 86%. — Subsequent treatment with benzaldehyde provides a new method for the prcpn. of keto-sugars. F. e. s. G. J. F. Ghittenden and R. D. Guthrie, Proc. Chem. Soc. 1964, 289 f. conditions s. Soc. (G) 1966, 695 also indole ring closures s. Soc. 1965, 3528. 

Zeolites can promote the cyclisation of ketone phenylhydrazones [43]. The phenylhydrazones of acetone and cyclohexanone cyclise in good yields to methylindole and tetrahydrocarbazole, respectively, in the presence of CaX zeolite. Zeolite beta is a highly selective catalyst for the synthesis of 2-benzyl-3-methylindole from phenylhydrazine and l-phenyl-2-butanone (e.g. equation 4.5) [44]. Clays have been reported to promote the ring closure of phenylhydrazones in a similar way [45]. Montmorillonite clay catalyses the ring closure of iV-benzylidene anilines with vinyl ethers to yield tetrahydroquinolines and azetidine derivatives [46]. 

C HuN40 Benzil-phenylbydrazon-emetyb phenylhydrazon 16 I 237. No.NP -Diphenyl-NP.benzyliden-NP -acetyl-benzhydrazidhi 16, 261. [ -Benzyliden-a-phenyl-hydrazino]-essig s4uTe-[d.benzyliden-a-phenyl-hydiazld]... 

C2iH BrCI ( 4-Brom-[Pg.2863]

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