2-PYRAZOLIN-5-ONES BEARING A BASIC DIALKYLAMINOALKYL SUBSTITUENT AT THE N1-POSITION: PREPARATION AND NMR SPECTROSCOPIC INVESTIGATIONS

摘要

2-Pyrazolin-5-ones (=tautomers to 5-hydroxypyrazols) bearing dialkylaminoyalkyl substituents at the ring nitrogen atom N-1 are prepared from the corresponding hydrazines and beta-ketoesters. Detailed NMR spectroscopic investigations (~1H, ~(13)C, ~(15)N) with the obtained compounds are undertaken and the tautomerism of such pyrazolones in solution is discussed.