Complexes and Condensation Products of Derivatives of the Pyrazolone Series with Oxygen-Containing Organic Compounds

F. Z. Gorfinкel

(Presented by Professor, Doctor of Chemical Sciences B. V. Tronov)

Antipyrine and pyramidon are analytical reagents [2, 3, 7] for bismuth, lead, cobalt, zinc, cadmium, mercury, and rare elements. But especially wide use in analytical practice [4, 5] has been made of condensed derivatives of antipyrine with various aldehydes of the type of dichlorohydrate of 4,4-diantipyrilalkyl-(aryl)-methane. We have synthesized several condensation products of antipyrine with aldehydes and ketones of the aliphatic and aromatic series and have studied the regularities of this reaction [9]. The dependence of the condensation reaction on the character of the hydrocarbon radicals in the molecules of the aldehydes and ketones has been established, as well as on the presence of a methoxy group, an iodine atom, and an ether oxygen in the ring. The activity of the carbonyl group is especially reduced in the presence of phenyl radicals (Tables 1, 2). In the literature, complexes of antipyrine with certain carboxylic acids are also known, such as salipyrine, acetosalipyrine, and others. They are medicinal substances and may, apparently, also find application as analytical reagents. It may be supposed that the complex-formation reaction of derivatives of the pyrazolone series with carboxylic acids can be used for separating certain groups of oxygen-containing organic compounds from mixtures with other compounds [1, 6, 8]. We have studied some regularities of the complex-formation reaction of antipyrine and pyramidon with various carboxylic acids of the aromatic series, with certain higher fatty acids, dicarboxylic acids, and hydroxy acids. The complexes of antipyrine and pyramidon with carboxylic acids that we studied were isolated from melts. The melts were obtained at a temperature of 75–140°. The resulting complexes were recrystallized from suitable solvents, most often from ether, and were analyzed for percentage nitrogen content by the Kjeldahl method, component content, and molecular weight. The molecular weight was determined by the cryoscopic method; the solubility of the complexes in various solvents was also determined. The complexes were obtained in yields of 65–93%. The complexes of pyramidon with carboxylic acids crystallized considerably more rapidly than the complexes of antipyrine with the same compounds. The solubility of the complexes was determined in water, alcohol, ether, benzene, toluene, and acetic acid at a temperature of 16–18° and upon heating. Most of the complexes of antipyrine and pyramidon obtained (Table 1) dissolved in water, alcohol, and benzene, and considerably more poorly in ether. In the interaction of antipyrine and pyramidon with carboxylic acids, complexes of the ammonium-salt type should be obtained. Depending on the nature of the starting substances, the complexes obtained are distributed among the following types: 1:1, 2:1. The results of the syntheses are given in Table 1.

Discussion of Results

The results of experiments with carboxylic acids show that dicarboxylic acids and hydroxy acids give complexes particularly well. The presence in

Table 1

Complexes of antipyrine and pyramidon with aromatic acids, some higher fatty acids, diacids, and hydroxy acids

Table 2

Composition and properties of condensed antipyrine derivatives with aldehydes and ketones of the saturated and aromatic series

the carboxylic acid radical, a halogen in the meta position relative to the carboxyl group, OH in the ortho- and meta positions, or combinations of several functional groups, such as an amino group and hydroxyl, two carboxyl groups, and a double bond, do not affect the character of complex formation of antipyrine and pyramidone with carboxylic acids. Owing to the stronger basic properties of pyramidone, crystallization of its complexes with carboxylic acids proceeds considerably more rapidly. Therefore pyramidone may be recommended as a strong complex-forming agent for the isolation of aromatic carboxylic acids, certain higher fatty acids, and dicarboxylic acids of the aliphatic series from mixtures with other oxygen-containing organic compounds. In the products of condensation of antipyrine with aldehydes, the presence of methoxyl groups, a nitrogen atom, or ether oxygen in the ring weakens the basic properties and leads to the formation not of dihydrochlorides of 4,4′-diantipyrine-alkyl-(aryl)-methane, but of monohydrochlorides of 4,4′-diantipyrine-alkyl-(aryl)-methane. The character of the condensation of antipyrine with aldehydes and ketones of the aliphatic and aromatic series is the same, but the condensation products obtained possess different physical properties, for example solubility, which leads to changes in the procedure for isolating the derivatives obtained.

Conclusions

1. Forty-two complexes of antipyrine and pyramidone with carboxylic acids were obtained.

2. The influence of the composition and structure of carboxylic acids on their ability to form complexes with antipyrine and pyramidone and on the properties of the complexes obtained was elucidated.

3. Nine condensed derivatives were obtained with aldehydes of the aliphatic and aromatic series.

References

1. Fialkov Ya. A. Sixth Conference on the Chemistry of Complex Compounds (abstracts), 63–66, 1953.

2. Zhivopistsev V. P. ZhOKh, 21, issue 3, 481–485, 1951.

3. Zhivopistsev V. P. Scientific Notes of Molotov University, 6, issue 3, 17–21, 1951.

4. Zhivopistsev V. P. Zh. Prikl. Khimii, 26, issue 3, 385–386, 1953.

5. Nature (Engl.), 171, No. 4345, 266, 1953.

6. Gusev S. N. and Beltes R. T. Zh. Anal. Khim., 7, issue 4, 219–225, 1952.

7. Terent’eva E. A. Zh. Uspekhi Khimii, 26, issue 9, 1025, 1957.

8. Terent’ev A. P. and Potapov M. V. Zh. Uspekhi Khimii, 26, issue 10, 1169, 1957.

9. Gorfinkel’ F. Z. Proceedings of the Tomsk Polytechnic Institute, 83, 135–143, 1956.

Corrections and Noted Misprints

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