Abstract
Effect of substituent in the para position with respect to the diazo group in diazotized orthanilic acid derivatives on the rate and selectivity of azo coupling with 7-acetylamino-4-hydroxynaphthalene-2-sulfonic acid was studied in citrate-phosphate buffers. The selectivity of azo coupling at the 3-position of the azo component almost does not depend on the nature of electron-donor substituent. Electron-acceptor groups considerably reduce the selectivity of formation of the 3-isomer. Previous conclusions, according to which the rate-determining stages are different depending on the site of azo coupling of diazotized orthanilic acid with 7-acetylamino-4-hydroxynaphthalene-2-sulfonic acid, were found to be also valid for some 5-substituted orthanilic acid derivatives. The rate-determining stage in the azo coupling at the 3-position can change upon introduction of strong electron-acceptor substituents capable of interacting with the diazo group. The contribution of the multicenter mechanism of deprotonation of the σ-complex with participation of water molecules was presumed to increase in going to the diazo components having electron-donor substituents.
Similar content being viewed by others
REFERENCES
Kornev, K.A. and Zheltov, A.Ya., Russ. J. Gen. Chem., 1998, vol. 68, no. 7, p. 1147.
Kornev, K.A. and Zheltov, A.Ya., Russ. J. Gen. Chem., 1999, vol. 69, no. 6, p. 962.
Zollinger, H., Helv. Chim. Acta, 1953, vol. 36, p. 1730.
Štérba, V. and Valter, K., Coll. Czech. Chem. Commun., 1972, vol. 37, p. 1327.
Kishimoto, S., Manabe, O., Hiyama, H., and Hirao, N., Nippon Kagaku Kaishi, 1972, no. 11, p. 2132.
Zhdanov, Yu.A. and Minkin, V.I., Korrelyatsionnyi analiz v organicheskoi khimii (Correlation Analysis in Organic Chemistry), Rostov-on-Don: Rostov. Gos. Univ., 1966.
Spravochnik khimika (Chemist's Handbook), Nikol'-skii, B.P., Ed., Moscow: Khimiya, 1964, vol. 3, p. 171.
Preparatyka Organiczna, Polaczkowa, W., Ed., Warsaw: Techniczne, 1954. Translated under the title Preparativnaya organicheskaya khimiya, Moscow: Khimiya, 1964, p. 471.
Scott, J.R. and Cohen, J.B., J. Chem. Soc., 1921, vol. 121, p. 2039.
Scott, J.R. and Cohen, J.B., J. Chem. Soc., 1923, vol. 123, p. 3190.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kornev, K.A., Zheltov, A.Y. Effect of Substituent in Diazotized Orthanilic Acid on the Azo Coupling with 7-Acetylamino-4-hydroxynaphthalene-2-sulfonic Acid in Citrate-Phosphate Buffers. Russian Journal of General Chemistry 73, 1095–1099 (2003). https://doi.org/10.1023/B:RUGC.0000007618.08375.43
Issue Date:
DOI: https://doi.org/10.1023/B:RUGC.0000007618.08375.43