[Antiarrhythmic active amidinohydrazones of substituted benzophenones. 3. The isomerization of (E)-2-amino-5-chlorobenzophenone amidinohydrazones]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 3. Mitteilung: Untersuchungen zur Isomerisierung von (E)-2-Amino-5-chlorbenzophenonamidinohydrazon.

The isomerization of the title compound in a preparative scale can be realized by acetylation/deacetylation or by influence of protons in dimethylformamide. The title compound is obtained als main product of the condensation of 2-amino-5-chlorbenzophenone and aminoguanidine if the reaction is carried out in the presence of formaldehyde.

[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.

[Anti-arrhythmic action of some amidinohydrazone substituted benzophenones. 1. Synthesis of new amidinohydrazone and N-phenylamidinohydrazone substituted benzophenones]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 1. Mitteilung: Synthese neuer Amidinohydrazone und N-Phenylamidinohydrazone substituierter Benzophenone.

The title compounds are synthesized as a rule by condensation of substituted benzophenones and derivatives of aminoguanidine in the presence of up to 2.5 moles of an anorganic acid. They can be obtained alternatively via corresponding hydrazones, thiosemicarbazones or methylthiothiocarbonylhydrazones.