Use of a Tin Cathode at Very Negative Potential

The effect of some parameters, such as the charge, current density and the kind of cathode material, on the amount of the »cathodic corrosion« of tin was investigated. Preparative electroreductions of cyclohexanone, a »dif- ficult to reduce« organic compound, were carried out as the test reaction to study the above mentioned effects on the possibility to realize preparative electroreductions, as well as for a comparison of the results with those obtained using Hg and Pb cathodes

Electrochemical Reduction of Intermediates in the Vitamin B6 Production. III. Reduction of Some Substituted Pyridones

Earlier papers in this series1\u272 treated the selective preparative reduction of substituted pyridines with four reactive functional groups (- N02 , -CH20CH3 , -CN and -Cl). This paper treats the electrochemical reduction of some substituted pyridones with three reactive functional groups (-N02 , -CH20CH" and -CN)

Properties and Use of a Lead Cathode at Very Negative Potential

The properties of lead cathodes at a very negative potential were studied on the basis of recent reports. The effects of the following factors on the »cathodic corrosion « of lead as well as on the preparative reduction of cyclohexanone as a test substance at lead cathode were investigated: the charge, current density, electrolyte composition, kind of the lead foil with respect to lead purity. The results of preparative electroreductions using both mercury and lead cathodes in identical reaction conditions were compared and discussed with regard to more practical aspects of their realization. The relation between the results obtained for the »cathodic corrosion« and for the overall cathode reaction at a lead cathode was also discussed. It was presumed that the overall reduction of cyclohexanone in the reaction conditions described in the paper (constant current density) consisted of two competitive reactions: a minor part of direct electron transfer and a predominant part of an indirect reduction using tetraalkylammonium lead

Electrochemical Reduction of Intermediates in the Vitamin B6 Production. II. Reduction of 2-Methoxymethyl-3-nitro-4-methyl- 5-cyano-6-chloropyridine

2-Methoxymethyl-3-nitro-4-methyl-5-cyano-6-chloropyridine (I) was reduced on a mercury-pool in an electrolytic cell with a diaphragm. A mixture of acetic and hydrochloric acid was used as catholyte and diluted hydrochloric acid as anolyte. Compound I was reduced at - 0.5 V to 2-methoxymethyl-3-amino-4-methyl- 5-cyano-6-chloropyridine (II) (yield 67-820/o). Compound II was reduced at - 0.9 V to 2-methoxymethyl-3-amino-4-methyl-5- cyanopyridine (Ill) (yield 54-83-0/o). Compound III was reduced at -1.1 V to 2,4-dimethyl-3-amino-5-cyanopyridine (IV) (yield 48-660/o Compound IV was reduced at constant current density to 2,4-dimethyl-3-amino-5-aminomethylpyridine (V) (yield 82,40/o). Polarographic waves of I, II, and III are defined and character of limiting currents was determined according to the usual criteria

Electrochemical Reduction of Intermediates in the Vitamin B6 Production. II. Reduction of 2-Methoxymethyl-3-nitro-4-methyl- 5-cyano-6-chloropyridine

2-Methoxymethyl-3-nitro-4-methyl-5-cyano-6-chloropyridine (I) was reduced on a mercury-pool in an electrolytic cell with a diaphragm. A mixture of acetic and hydrochloric acid was used as catholyte and diluted hydrochloric acid as anolyte. Compound I was reduced at - 0.5 V to 2-methoxymethyl-3-amino-4-methyl- 5-cyano-6-chloropyridine (II) (yield 67-820/o). Compound II was reduced at - 0.9 V to 2-methoxymethyl-3-amino-4-methyl-5- cyanopyridine (Ill) (yield 54-83-0/o). Compound III was reduced at -1.1 V to 2,4-dimethyl-3-amino-5-cyanopyridine (IV) (yield 48-660/o Compound IV was reduced at constant current density to 2,4-dimethyl-3-amino-5-aminomethylpyridine (V) (yield 82,40/o). Polarographic waves of I, II, and III are defined and character of limiting currents was determined according to the usual criteria

Electrochemical Reduction of Intermediates in the Vitamin B6 Production. III. Reduction of Some Substituted Pyridones

Earlier papers in this series1\u272 treated the selective preparative reduction of substituted pyridines with four reactive functional groups (- N02 , -CH20CH3 , -CN and -Cl). This paper treats the electrochemical reduction of some substituted pyridones with three reactive functional groups (-N02 , -CH20CH" and -CN)

Use of a Tin Cathode at Very Negative Potential

The effect of some parameters, such as the charge, current density and the kind of cathode material, on the amount of the »cathodic corrosion« of tin was investigated. Preparative electroreductions of cyclohexanone, a »dif- ficult to reduce« organic compound, were carried out as the test reaction to study the above mentioned effects on the possibility to realize preparative electroreductions, as well as for a comparison of the results with those obtained using Hg and Pb cathodes