Study of basic deuterium exchange in series of 4-hydroxyisoquinoline, 3-hydroxyquinoline, and 8-hydroxyquinoline derivatives

Abstract

1. A study was made of the sequence of substitution and the exchange rate of the protons of some 3-hydroxyquinoline, 8-hydroxyquinoline, and 4-hydroxyisoquinoline derivatives. 2. The most reactive in 4-hydroxyisoquinoline is the 3 position, and in 4, 8-dihydroxyisoquinoline the 7 position of the isoquinoline ring. 3. The insertion of the annulated benzene ring in the 4, 5 position of theβ-pyridol ring increases the exchange rate of the ortho- and para-protons relative to the OH group. 4. The most reactive in the 3-hydroxy- and 2-methyl-3-hydroxyquinolines is the C4H proton, while in the 3, 5-dihydroxy- and 8-hydroxyquinolines the protons of the phenol ring are the most reactive. 5. The insertion of the annulated benzene ring in the 5,6 position of 3-hydroxypyridine changes the sequence of substitution of the protons of theβ-pyridol ring.