A study of substituent effects on the NH bond in alkyl and aryl 4,6-disubstituted-3-cyano-2-pyridones

Abstract

Substituent effects on the IR stretching frequencies and 1H-NMR chemical shifts of the pyridone NH group in 4- and 6-disubstituted alkyl and aryl 3-cyano- 2-pyridones were investigated. The bands most sensitive to substituent effects from the broad and multiple IR NH band for each compound were selected by a computer calculation. The selected values of the IR frequencies and the determined 1H-NMR chemical shifts were subjected to LFER analysis, by correlations with the Hamett σm/p and Swain-Lupton F and R substituent constants.

U radu je razmatran uticaj supstituenata na IR frekvencije i 1H-NMR hemijska pomeranja za piridonsku NH grupu u 4- i 6-disupstituisanim alkil i aril 3-cijano-2-piridonima korišćenjem principa linearne korelacije slobodne energije. Za izračunavanja su primenjene Hametove σm/p konstante kao i Swain-Lupton konstante supstituenata F i R. Razvijen je kompjuterski metod za izbor IR NH traka najosetljivijih na uticaj supstituenata.