Search

It is shown by means of IR spectra that the reaction of phthalonitrile with sodium methoxide in benzene in the presence of traces of water or methanol proceeds via a series-parallel mechanism in two steps to give cyclic products. The proposed structure of the intermediate is an oligomeric isbindolenine chain with terminal NNa and OCH3 groups. The final product is the sodium salt of monomethoxyiminoisoindolenine. The analogous reaction in methanol proceeds at a higher rate that makes it impossible to isolate or detect the intermediate; the final product is 1,1-dimethoxy-3-iminoisoindoline.

Die nach bekannten Methoden dargestellten Komplexe (I) und (II) werden IR-, elektronenspektrometrisch und rontgenographisch charakterisiert.

Phenanthrenequinone monoxime and its mono-, di-, and trinitro derivatives were synthesized. The acidity constants and their variation with the number and position of nitro groups were determined. The electronic and IR spectra of the nitro compounds were studied. The bands in the electronic spectra were assigned based on quantum-chemical calculations in the Pariser—Parr—Pople approximation. Correlations between the pKa values and some calculated characteristics of the compounds under study were found.

The molecular and crystal structures of 4-acetamido-2,3-dimethyl-1-phenylpyrazol-5-one (1) and 4-maleylamido-2,3-dimethyl-l-phenylpyrazol-5-one (2) were studied. The molecular conformations are stabilizedvia systems of intermolecular hydrogen bonds between the amide groups and the carbonyl oxygen atoms of the pyrazolone rings. The conformation of compound 2 is additionally stabilizediva an intramolecular interaction between the carboxyl group and the amide oxygen atom. According to the IR spectral data, protonation of the compounds under study in an acetonitrile solution occurs at the carbonyl oxygen atom of the pyrazolone ring, which is also confirmed by the UV spectral data.

Ammonium 2,3,5,6-tetraoxo-4-nitropyridinate was shown to exist as stable dimers and act as a weak electrolyte in both a crystalline state and aqueous solutions. In a strongly alkaline medium, ammonium cations were successively replaced by sodium cations. The molecular and crystal structures of sodium 2,3,5,6-tetraoxo-4-nitropyridinate trihydrate and sodium ammonium bis(2,3,5,6-tetraoxo-4-nitropyridinate) monohydrate were established, and their spectroscopic characteristics were determined.

The halogenation of 5-benzyl-3-hydroxypyridine proceeds with the formation of 2,6-dihalo-substituted compounds. The presence of a benzyl group in the 5 position activates the 6 position of the β-pyridol ring with respect to electrophilic attack.

1. The halogenation (bromination and iodination) of 4-hydroxyisoquinoline was studied. 2. The halogenation of 4-hydroxyisoquinoline is directed initially to the 3 position and then to the 1 position of the isoquinoline ring.

1. The nitration of 2-methoxy-3-hydroxypyridine was studied. 2. The nitro group initially enters the 4 position and then the 6 position of the pyridine ring. 3. The main orienting agent during the nitration of 2-methoxy-3-hydroxypyridine is theβ-hydroxy group.

1. The aminomethylation and azo-coupling of 5-benzyl-3-hydroxypyridine take place at the 2 position of theβ-pyridinol ring. 2. The presence of a benzyl group in the 5 position of theβ-pyridinol ring prevents both aminomethylation and azo-coupling in the 6 position.

1. A study was made of the aminomethylation of 2,5-dihydroxypyridine and N-methyl-3-hydroxy-2-pyridone. 2. The aminomethylation of 2,5-dihydroxypyridine and N-methyl-3-hydroxy-2-pyridone is directed to the 6 position of the pyridine ring.