Condensations compounds

Qualitative Analysis. Several quaUtative analyses can be employed. For example, in the oxamide method (59), oxaUc acid is first heated at approximately 200°C with concentrated aqueous ammonia in a sealed tube. When thiobarbituric acid is added and heated to 140°C, a condensed compound of red color forms. The analysis limit is 1.6 pg. In the diphenylamine blue method (59,60), oxaUc acid is heated with diphenylamine to form a blue color, aniline blue. The analysis limit is 5 pg. 

Citral forms condensation compounds with sulphites and lacid sulphites which are exceedingly useful in the estimation of the alde-hy. Tiemann has isolated three separate hydrosulphonic acid compounds. The normal bisulphite compound is best prepared by shaking citral with a hot solution of sodium bisulphite containing free sulphurous acid. 

Table 7 Overview of ID50 values in vitro of condensation compounds of Bu2SnO with F -containing carboxylic acids against MCF-7 and WiDr...

XIIA Bicyclic condensed compounds except naphthalene. (1948.)... 

The solubility of the mandelic acid-acetone condensation compound in liquid ammonia at its boiling point is approximately 10 g. per 100 cc. 

The diagrams calculated by the methods described differ to some extent from many available in the literature in that they omit the predominant solution compound in areas where a condensed compound also forms. This greatly simplifies the diagrams without impairing their usefulness for most purposes. 

However, attempts from the authors of [125] to synthesize fused imidazoles involving isoxazols, pyrazols, or 1,3,5-triazols as primary amines in the presence of catalytic amounts of glacial acetic acid were unsuccessful and led either to the formation of complex product mixtures or even to the formation of Ugi-type four-component condensation compounds in low yields. 

Acid-catalyzed condensation of bicyclic ozonides with aldehydes and ketones, in the presence of hydrogen peroxide, leads to the formation of bicyclic peroxide analogs of acetals in low yields, as shown in equation 91 for the condensation of the ozonide of 1-phenylcyclopentene (266) with benzaldehyde. The structure of compound 267, with the preferred ring conformation as shown, was determined by XRD analysis . The same method served to demonstrate that the condensation compound 16c is unique, with structure 254 . 

Amine-aldehyde condensation compounds are believed to react with H2S to form more complex carbon-sulfur bonded products. 

Many of the pseudoazulenes summarized in Table I were prepared from the corresponding quaternary salts (90 and 92) by deprotonation reactions (Scheme 3). This type of synthesis is especially advantageous for azalenes and oxalenes, although thialenes are seldom prepared in this way (e.g., systems 37,107 51,137 and 67l76) because of the difficult synthesis of the corresponding thiopyrylium salts.204 However, with the exception of condensed compounds (e.g., systems 35,104,105 38,94 61,92 72,24-29,32-36 and 73,35,185,186 tjjjs approach also has disadvantages for the preparation of azalenes (93 X = NR) of the [c]-series. 

Concerning phosphorus chemistry, the synthesis of condensed compounds, optically active, with pentaco-ordinated phosphorus adopting helicoidal or macrocyclic structures, represents, in our opinion, significant progress. Thus, hydroxyphosphoranes lb, 2b are tautomers of hydroxyphosphoric esters, similar to phosphoric esters of natural polyhydroxylated compounds. 

The condensation of P-naphthisatin 32 with the ketones 33 takes place through the methyl group of the latter. Here the tricyclic condensed compounds 34 are formed with almost quantitative yields [24],... 

The fundamental object of his researches differs from that of Gattermann, in that Lob undertakes to establish the separate phases of the reduction of the nitro-group. This he accomplishes by the addition of formaldehyde to the electrolyte under varying conditions, and as a result the intermediate products, at the moment of their formation, combine with formaldehyde, producing condensation compounds which do not undergo further decomposition. By regulating the potential or density of the current the reaction can at... 

In the reaction of 3-nitro-5-R-l,2,4-triazolate-anion with 3,5-dinitro-l-(2-oxo-propyl)-l,2,4-triazole both the products of nucleophilic substitution in position 5 and condensed compounds [5-methyl-5-(3-nitro-5-R-l,2,4-triazol-l-yl)-5,6-dihydroxazolo[3,2-b]-l,2,4-triazoles] are formed. Their structures were established by H NMR and IR spectroscopy [585],... 

Hatfield, W. E. Properties of Magnetically Condensed Compounds, in Theory and Applications of Molecular Paramagnetism (eds. Boudreaux, E. A., Mulay, L. N.) New York, Wiley 1976... 

Hydrolysis experiments " with artificially produced condensation compounds were carried out, and the curves relating the per cent increase in reducing power with the rate of hydrolysis of the unfermentable material were found to be similar to those obtained with the reducing substances derived from cane molasses. 

These condensation compounds are not easily reduced, the follomng reagents being without effect zinc and acetic or hydrochloric acid aluminium powder and sodium hydroxide sodium and alcohol. 

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