[Spectroscopic and chromatographic studies on photochemical isomerism of alpha, beta-diunsaturated ketones]. / Spektroskopische und chromatographische untersuchungen zur photochemischen isomerisierung von alpha,beta-diungesättigten ketonen.

Spectroscopic (UV, IR, NMR, MS) and chromatographic (HPLC, GC) investigations show for alpha,beta-diunsaturated ketones with one double bond fixed in a cyclohexene-, furan- or thiophene ring in most examples a photochemical Z/E-isomerization in solution by the influence of light. Investigations of conformers by IR and NMR however are not influenced during usual operations and light protection is not nessessary.

About the conformations of alpha,beta-diunsaturated ketones.

Substituted 1-(cyclohexenyl)-3-phenylpropen-1-ones, 1-(2-furyl)-3-phenylpropen-1-ones, and 1-(2-thienyl)-3-phenylpropen-1-ones, ketones with 1,4-pentadien-3-one structure, prefer in solution, and at room temperature, according to 1H NMR and IR investigations the s-trans/s-cis conformation. For some compounds the participation of other conformers in the equilibrium could be demonstrated. These results were obtained by a qualitative study of 25 derivatives in different solvents, and comparison with results from MM+, PM3, AM1 or MMX calculations.

[Anti-arrhythmia action of amidinohydrazone substituted benzophenones. 6. Parenteral drug forms of (Z)-2-amino-5-chlorobenzophenone amidinohydrazone acetate (G 256)]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 6. Mitteilung: Parenterale Arzneiformen für des (Z)-2-Amino-5- chlorbenzophenonamidino-hydrazonacetat (G 256).

The combination of lyophilized G 256 and a solvent ampoule is recommended as an optimal variant for the application of the compound. In the lyophilized substance both the hydrolysis and the isomerisation are reduced so it is stable enough for the required period of usability.

[Antiarrhythmia active amidinohydrazone substituted benzophenones. 5. The stability of (Z)-2-amino-5-chlorobenzophenone amidinohydrazone acetate in solution]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 5. Mitteilung: Untersuchungen zur Stabilität des (Z)-2-Amino-5- chlorbenzophenonamidinohydrazonacetats in Lösung.

The aqueous solution of the title compound can be used for injection for one year if it is stored at room temperature and under light protection. Under these conditions 8% of the E-isomer are produced. The reaction is reversible at day light. Red coloured products of decomposition are formed by long lasting influence of light. At higher temperatures or at sterilisation several products of decomposition are formed which structure is elucidated. For these decomposition a scheme is proposed.

[Antiarrhythmic active amidinohydrazones of substituted benzophenones. 4. The photoisomerization of (Z)- and (E)-2-amino-5-chlorobenzophenone amidinohydrazones and the corresponding (E)-N-phenylamidinohydrazone]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 4. Mitteilung: Untersuchungen zur Photoisomerisierung von (Z)- und (E)-2-Amino-5-chlorbenzophenonamidinohydrazon sowie des entsprechenden (E)-N-Phenylamidinohydrazons.

The title compounds undergo a photoisomerization by irradiation. If the E-isomers are irradiated by light of a wavelength of an absorption maximum typical for them, they can be converted quantitatively to the corresponding Z-isomers. In case that the synthesis of analogs of the title compounds give only one configurational isomer, sometimes the missing one can be obtained by photoisomerization.

[Antiarrhythmic amidinohydrazone substituted benzophenones. 2. Preparation and determination of configuration of (Z)- and (E)-2-amino-5-chlorobenzophenone amidinohydrazone salts]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 2. Mitteilung: Darstellung und Konfigurationszuordnung von (Z)- und (E)-2-Amino-5-chlorbenzophenonamidinohydrazonsalzen.

The configurational isomers of the 2-amino-5-chlorbenzophenoneamidinohydrazones could be obtained as TLC pure samples by fractionating crystallization of the product mixture. The determination of their configuration by comparison of the UV spectra with the corresponding oximes could be confirmed by X-ray structure analysis.

[Extraction behavior of polypropylenes. 87. Problems in the use of plastic containers for fluid drugs]. / Extraktionsverhalten von Polypropylen. 87. Mitteilung: Zur Problematik des Einsatzes von Kunststoffbehältern für flüssige Arzneizubereitungen.

Studies on the extraction of antioxidants in different polypropylene samples subjected to variable extraction terms proved that storing neutral or faintly acid infusion solutions or those with an ethanol content up to 10% for several months, the extracted antioxidants are in allowable ranges. Insignificantly increased amounts of antioxidants are delivered to alkaline solutions and to ethanol/water mixtures having increased ethanol contents. The methods and specified limiting values of the GDR pharmacopoeia have been consulted for the semiquantitative estimate of extractives.