Ferrocene Compounds. V. Indirect Electrochemical Reduction of Acetylferrocene

2,3-Diferrocenyl-2,3-butanediol (II) has been obtained by the indirect electrochemical reduction of acetylferrocerie (I) using an electrochemically generated sodium amalgam. The approximative value of the half-wave reduction potential of acetylferrocene (I) . and the stereochemistry of (II) has been determined. Pinacol (II) was rearranged to 2,3-diferrocenylbutane-3-on (III) , dehydrated to 2,3-diferrocenyl-1,3-butadiene (IV) and anhydride of 4,5- diferrocenyl- 4-cyclohexene-1,2-dicarboxylic aC!id (V) was formed by the Diels-Alder reaction of (IV)

Ferrocene Compounds. III*. On the Tautomerism and Reactions of Some Derivatives. of B-Ferrocenoylacrylic acid

The tautomerism of Fc-CO-CH2-CO-C02R (Fe = ferrocenyl) (I, R = H; II, R = C2H5) and Fc-CO-CH2-C(= NR)-:- C02C2H5 (III, R = H; IV-VI, R =alkyl; VII-IX, R = aryl) has been· investigated on the basis of their IR, UV and NMR spectra. Reactions of ester II with ammonia and primary aliphatic and aromatic amines, as well as of the compounds I-IX with hydroxylamine hydrochloride and hydrazine hydrate have been studied

Ferrocene Compounds. I. Acetylferrocene and Diethyl Oxalate Condensation Products and Their Derivatives

By the reaction of acetylferrocene with diethyl oxalate l ,6- diferrocenyl-1,3,4,6-hexanetetrone (I), a, y-dioxo-y-ferrocenylbutyric acid (II) and its ethyl ester (III) were prepared in a yield of 78.3, 55.1 and 51.5°/o resp. The polyoxo compounds I, II and III were converted through the action of suitable reagents into 2,3-bis (ferrocenoy lmethy l)quinoxaline (IV), 5,5\u27 (3\u27)-diferroceny 1-1, 1\u27 -dipheny l-3,3\u27 (5\u27)-dipyrazoly l (V), 3(5)-ferrocenyl-1-phenyl-5(3)-pyrazolecarboxylic acid (VI) and its ethyl ester (VII) and 3-ferrocenoylmethylene- 2-piperazinone (VIII)

Ferrocene Compounds. I. Acetylferrocene and Diethyl Oxalate Condensation Products and Their Derivatives

By the reaction of acetylferrocene with diethyl oxalate l ,6- diferrocenyl-1,3,4,6-hexanetetrone (I), a, y-dioxo-y-ferrocenylbutyric acid (II) and its ethyl ester (III) were prepared in a yield of 78.3, 55.1 and 51.5°/o resp. The polyoxo compounds I, II and III were converted through the action of suitable reagents into 2,3-bis (ferrocenoy lmethy l)quinoxaline (IV), 5,5\u27 (3\u27)-diferroceny 1-1, 1\u27 -dipheny l-3,3\u27 (5\u27)-dipyrazoly l (V), 3(5)-ferrocenyl-1-phenyl-5(3)-pyrazolecarboxylic acid (VI) and its ethyl ester (VII) and 3-ferrocenoylmethylene- 2-piperazinone (VIII)

Syntheses of New Pyrazolo-, and Tetrazolopyridines

By the reaction of cyanoacetamide and acetylacetone we prepared some new pyrazolo(3,4-b) pyridines (8, Sa, 9) and tetrazolo( l,5-a) pyridines (6, 12, 16) over several reaction steps. Azido- tetrazolo isomerisation of tetrazolo (l,5-a) pyridines (6, 12, 16) has been investigated on the basis of their i. r. and n. m. r. spectra in three solvents (dimethyl sulfokside, chloroform and trifluoroacetic acid). Compound 8 can be detected as a tetrazolo tautomer in the solid state as well as in solutions. Compound 16 in the solid state exists only in the tetrazolo form, while in solutions it exists in both forms. Compound 12 in the solid state exists only in the azido form, while in solutions it exists in both forms

Ferrocene Compounds. V. Indirect Electrochemical Reduction of Acetylferrocene

2,3-Diferrocenyl-2,3-butanediol (II) has been obtained by the indirect electrochemical reduction of acetylferrocerie (I) using an electrochemically generated sodium amalgam. The approximative value of the half-wave reduction potential of acetylferrocene (I) . and the stereochemistry of (II) has been determined. Pinacol (II) was rearranged to 2,3-diferrocenylbutane-3-on (III) , dehydrated to 2,3-diferrocenyl-1,3-butadiene (IV) and anhydride of 4,5- diferrocenyl- 4-cyclohexene-1,2-dicarboxylic aC!id (V) was formed by the Diels-Alder reaction of (IV)

Ferrocene Compounds. VII. The Stobbe Condensation of Formylferrocene with Diethyl Glutarate

The Stobbe condensation of formylferrocene with diethyl glutarate in the presence of potassium tert-butoxide gave (E)-1-ethyl hydrogen 2-ferrocenylmethyleneglutarate (I), which was converted by the action of diazomethane to (E)-1-ethyl 5-methyl 2-ferrocenylmethyleneglutarate (II). The configurations of compounds I and II are assigned through study of their 1H-NMR and IR spectra. This stereochemical assignment is supported by the conversion df compound I to cyclopentadienyl(5,6-dihydro-4-oxo-7-ethoxycarbonylazulenyl) iron (III), which was hydrolized to the corresponding acid (VI). The same acid VI was obtained from half ester I via the corresponding diacid IV and anhydride V. The stereoselectivity of the Stobbe condensation is discussed

Ferrocene Compounds. III*. On the Tautomerism and Reactions of Some Derivatives. of B-Ferrocenoylacrylic acid

The tautomerism of Fc-CO-CH2-CO-C02R (Fe = ferrocenyl) (I, R = H; II, R = C2H5) and Fc-CO-CH2-C(= NR)-:- C02C2H5 (III, R = H; IV-VI, R =alkyl; VII-IX, R = aryl) has been· investigated on the basis of their IR, UV and NMR spectra. Reactions of ester II with ammonia and primary aliphatic and aromatic amines, as well as of the compounds I-IX with hydroxylamine hydrochloride and hydrazine hydrate have been studied

Synthesis of β-Phenyl-α,β-dioxo-propionanilide. Peptide-Like Polyoxo Compounds

In the first communication of this series it was shown that 2,3,4-triketotetrahydropyridine exercises a diaibetogenic activity on white rats, the same as alloxane. It, was, further, suggested, fill.at the grouping -COCOCONH- may be responsible for this activity of 2,3,4-triketo-tetrahydropyridine, as for that of alloxane

Electrochemical Reduction of Acetonylacetone in Hydrochloric Acid

The electrochemical reduction of acetonylacetone on a mercury cathode in aqueous hydrochloric acid medium has been studied. It has been shown that the electroactive species is the protonated form of acetonylacetone. The experimental results indicate -that the rate of electrochemical reduction is dependent upon the preceding chemical protonation step and/or adsorption of the electroactive species. The electrolysis at controlled potential (- 1.2 V vs. S. C. E .) yielded the following products : acetaldehyde; acetone, acetic acid, 2,5-hexanediol and 2,5-dimethyltetrahydrofuran. Possible mechanistic routes leading to the formation of these products are discussed