N-Unsubstituted 1,2,4-Triazole-3-carbaldehydes

1971 ◽  
Vol 24 (2) ◽  
pp. 393 ◽  
Author(s):  
EJ Browne

A series of N-unsubstituted 1,2,4-triazole-3-carbaldehydes has been prepared by acid hydrolysis of their methyl or ethyl acetals. Those with 5-aryl substituents have been shown to dimerize in the solid state to carbonyl-free hemiaminals. P.m.r. and infrared spectra indicate that monomeric 1,2,4-triazole-3-carbaldehydes are present in solution, the dimers being reformed on removal of the solvents. Parallels are drawn with benzimidazole-2-carbaldehyde, to which a similar structure has been assigned. With non-aromatic 5-substituents the hemiaminal becomes less stable, and 1,2,4-triazole-3-carbaldehyde, itself, exists predominantly in the carbonyl form. Mass spectra were consistent with essentially normal aldehyde structures.

2010 ◽  
Vol 11 (5) ◽  
pp. 1376-1386 ◽  
Author(s):  
Anayancy Osorio-Madrazo ◽  
Laurent David ◽  
Stéphane Trombotto ◽  
Jean-Michel Lucas ◽  
Carlos Peniche-Covas ◽  
...  

1975 ◽  
Vol 28 (3) ◽  
pp. 525 ◽  
Author(s):  
JD Stevens

Two septanose derivatives of D-glucose, 1,2:3,4-di-O-isopropylidene-α-D-glucoseptanos(e4 a) and 2,3:4,5-di-O-isopropylidene-D-glucoseptanos(e5 a), have been isolated from the mixture of products formed by treating D-glucose with acidified acetone. Acid hydrolysis of (4a) yielded 1,2-O-isopropylidene- α-D-glucoseptanose which has been converted into a mixture of (4a) and a third D-glucoseptanose derivative, 1,2:4,5-di-O-isopropylidene-α-D-glucoseptanose (8a). Methylation of (5a) yielded the two D-glucoseptanoside derivatives, methyl 2,3:4,5-di-O-isopropylidene-α-D-glucoseptanoside and methyl 2,3:4,5-di-O-isopropylidene-β-D-glucoseptanosiwde, which have been selectively hydrolysed to give methyl α (and β-)-D-glucoseptanosides. Conformations of these various septanose compounds are proposed on the basis of n.m.r. parameters and these conformations are compared with those found in the solid state by X-ray analysis.


1973 ◽  
Vol 51 (11) ◽  
pp. 1527-1536 ◽  
Author(s):  
C. N. Joo ◽  
C. E. Park ◽  
J. K. G. Kramer ◽  
M. Kates

Monophytanyl phosphate was synthesized by phosphorylation of phytanol with diphenylphosphoryl monochloride followed by catalytic hydrogenolysis of the phenyl groups; the product was isolated as the dipotassium salt. The phytanyl pyrophosphate was prepared by phosphorylation of phytanol with monophenylphosphoryl dichloride followed by aminolysis and saponification of the resulting phytanylmonophenylphosphoryl monochloride to the phytanyl phosphoramidate. The latter, as the cyclohexylamine salt, was reacted with dioxane diphosphate in the presence of pyridine to give the desired phytanyl pyrophosphate isolated as the tripotassium salt. Alternatively, the phytanyl pyrophosphate was made from phytanyl monophosphate via the phosphomorpholidate. The 2-phytenyl (phytyl) pyrophosphate was synthesized more directly by phosphorylation of phytol with di-(triethylammonium) phosphate in the presence of trichloroacetonitrile in acetonitrile as solvent. The phytyl pyrophosphate and the accompanying phytyl monophosphate were isolated as tri- and diammonium salts, respectively. These mono- and pyrophosphates were characterized by elementary analysis, infrared spectra, and behavior towards acid hydrolysis; the hydrolysis products formed are characteristic of the phytyl or phytanyl phosphate hydrolyzed and may be used for their identification.


2009 ◽  
Vol 100 (20) ◽  
pp. 4758-4765 ◽  
Author(s):  
Carsten Sievers ◽  
Teresita Marzialetti ◽  
Travis J.C. Hoskins ◽  
Mariefel B. Valenzuela Olarte ◽  
Pradeep K. Agrawal ◽  
...  

1992 ◽  
Vol 12 (3) ◽  
pp. 335-354 ◽  
Author(s):  
Jean Bouchard ◽  
Ralph P. Overend ◽  
Esteban Chornet ◽  
Marie-Rose Van Calsteren

1966 ◽  
Vol 19 (5) ◽  
pp. 741 ◽  
Author(s):  
CG Barraclough ◽  
J Stals

The infrared and mass spectra of MoO2Cl2, MoO2Br2, WO2Cl2, and WO2Br2 in the gas phase have been studied. The vapours contain mostly monomeric molecules but there is also a small amount of relatively unstable dimeric species present in each case. In inert solvents MoO2Cl2 and MoO2Br2 are dimeric and the infrared spectra are reported. In the solid state all four compounds are polymeric and the absence of the characteristic M = O infrared frequency suggests that only bridging oxygen atoms can be present. X-ray powder diffraction data suggest that the four compounds are isomorphous.


1969 ◽  
Vol 47 (20) ◽  
pp. 3823-3830 ◽  
Author(s):  
T. Eliades ◽  
R. O. Harris ◽  
P. Reinsalu

A study of acid hydrolysis of acidopentaammines of ruthenium(III) shows that aquation is not the only reaction taking place. For the halopentaammines, both in the presence and absence of light, reduction occurs with the formation of ruthenium(II) and free halogen. When azide, instead of halide ion, is coordinated to the metal, ruthenium(II) nitrogen complexes can be prepared. The solid state decomposition of [Ru(trien)(N3)2]+ ion to [Ru(trien)N3N2]+ is described.


1960 ◽  
Vol 38 (8) ◽  
pp. 1381-1394 ◽  
Author(s):  
D. A. Andrews ◽  
F. G. Hurtubise ◽  
H. Krässig

The presence of monothiocarbonate substituents in viscose has been demonstrated by the infrared spectra of the gases evolved during the acid hydrolysis of cellulose xanthate salts and viscose. A comparison of the results of various methods of sulphur determination and the results obtained by ultraviolet spectroscopy has been made. The results of investigations on sodium cellulose monothiocarbonate preparations support the concept of monothiocarbonate substitution.


1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.


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