scholarly journals The Base-catalyzed Condensation of o-Nitroacetophenone. II. The Ozonolysis of Methyl Ether of Compound A, a Condensation Product, and the Structure of Compound B, Another Product

1964 ◽  
Vol 37 (11) ◽  
pp. 1681-1684 ◽  
Author(s):  
Takeo Sakan ◽  
Kousuke Kusuda ◽  
Toshio Miwa
1930 ◽  
Vol 2 (3) ◽  
pp. 214-217 ◽  
Author(s):  
Harold Hibbert ◽  
J. G. Morazain

Isopropylidene glycerol, prepared in neutral medium by the action of anhydrous copper sulphate as condensing agent, was methylated with silver oxide and methyl iodide; the product yielded only glycerol α-methyl ether on hydrolysis, thus proving the absence of any six-membered ketal in the condensation product of glycerol and acetone.The properties of both glycerol α- and β-methyl ethers have been carefully redetermined.A table of the isomeric acetals and ketals summarising their physico-chemical constants is given, in view of their usefulness as "type compounds" in investigations relating to fats, carbohydrates and polysaccharides.


1937 ◽  
Vol 15b (11) ◽  
pp. 480-485 ◽  
Author(s):  
John A. McRae ◽  
Léo Marion

The neutral product of the condensation of phenylacetaldehyde with ethyl sodiocyanoacetate when distilled under low pressures loses the elements of ethyl alcohol and forms 1-hydroxy-2-naphthoic nitrile. This is identical with the synthetic substance prepared through a series of reactions from α-naphthol. The methyl ether has been prepared from both the synthetic substance and the product of the condensation. 1-Hydroxy-2-naphthoic nitrile can be coupled readily with p-nitrobenzenediazonium chloride. The evidence relating to the structure of the neutral condensation product is reviewed.


1932 ◽  
Vol 7 (6) ◽  
pp. 629-642 ◽  
Author(s):  
Muriel E. Platt ◽  
Harold Hibbert

The work represents an extension of the "Hibbert-Michael ring partition theory" to the interaction of α-phenyl glycerol with acetone and p-nitrobenzaldehyde respectively. The α-phenyl glycerol was prepared in the form of a pure crystalline product from cinnamyl alcohol and on condensation with acetone yielded the two expected, isomeric, five-membered (dioxolane) ring compounds. These two isopropylidene derivatives were isolated and their structures definitely determined by the usual hydrolysis and methylation technique. In this manner the corresponding α- and γ-methyl ethers of α-phenyl glycerol were isolated, the identity of which had been previously settled by direct synthesis employing well-established reactions.The β-methyl ether of α-phenyl glycerol was obtained by methylating crystalline 1:3 p-nitrobenzylidene α-phenyl glycerol and then hydrolyzing the ether.Condensation of p-nitrobenzaldehyde with α-phenyl glycerol should yield, according to the "ring partition principle", one six- and two five-membered cyclic acetals.The crystalline isomer separating from the crude condensation product was shown to be the six-membered cyclic acetal. Removal of this left a viscous oil containing the five-membered acetals which, on methylation, and subsequent hydrolysis, yielded a small amount of the γ-methyl ether of α-phenyl glycerol, thus indicating the presence of some 1:2 p-nitrobenzylidene glycerol in the original reaction product. Due to the large number of theoretically possible five-membered rings it was not found possible to isolate, or prove the presence of, both five-membered acetals in the oil left after removal of the crystalline six-membered acetal. Presumably both of the structural five-membered acetals were formed, but due to their mutual solubility relations it was not possible to bring about a separation of crystalline forms.


Author(s):  
B. J. Grenon ◽  
A. J. Tousimis

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.


1955 ◽  
Author(s):  
Saul B. Sells ◽  
John R. Barry ◽  
David K. Trites ◽  
Herman I. Chinn
Keyword(s):  

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.


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