Practical Outcome of Azaphthalimide Reduction with Zn/AcOH at Various Temperatures

Title: Practical Outcome of Azaphthalimide Reduction with Zn/AcOH at Various Temperatures

Volume: 3 Issue: 5

Author(s): Mikhail Krasavin, Dmitry V. Kravchenko, Tatiana D. Talismanova, Vladimir V. Koleda, Olga Ushakova and Vladislav Z. Parchinsky

Affiliation:

Keywords: Azaphthalimides, chemoselective reduction, isoindolones, intramolecular hydrogen bond, combinatorial compound libraries

Abstract: Reduction of 4-aza- and 5-azaphthalimides with Zn dust in acetic acid resulted in two distinct outcomes: i) in the 4-aza series, the reduction process stopped at the stage of 3-hydroxy-4-azaisoindolin-1- ones (isolated in 69-90% yield), presumably, stabilized by an intramolecular hydrogen bond; more forcing condition (110, 2 days) are required to obtain 4-azaisoindolin-1-ones; ii) in the 5-aza series, even at low temperatures (∼10), overreduction could not be avoided; practical yields of 4-azaisoindolin-1-ones (59- 85%) were achieved using elevated temperatures (50°C). The method described offers a practical alternative to hitherto reported sodium borohydride reduction of 4-azaphthalimides, which suffers from poor selectivity and isolated yields. Reductive manipulation of 5-azaphthalimides was studied for the first time.

Cite this article as:

Krasavin Mikhail, Kravchenko V. Dmitry, Talismanova D. Tatiana, Koleda V. Vladimir, Ushakova Olga and Parchinsky Z. Vladislav, Practical Outcome of Azaphthalimide Reduction with Zn/AcOH at Various Temperatures, Letters in Organic Chemistry 2006; 3 (5) . https://dx.doi.org/10.2174/157017806776611890