A MULTINUCLEAR NMR-STUDY (H-1, C-13, N-15) OF 1-MONOSUBSTITUTED PYRAZOLES

The chemical shifts and coupling constants of twenty-three pyrazoles b earing different substituents at position 1 have been studied by H-1, C-13 and N-15 NMR spectroscopy in solution. Three new pyrazoles -pyraz olyl-P,P,P-triphenylphospha-lambda(5)-azene, sodium 1-hydroxypyrazolat e and 1-trifluoromethanesulfonylpyrazole) have been prepared; moreover , to assign the signals of some compounds, two other pyrazoles have be en synthesized labelled in both nitrogen atoms with N-15 (l-benzyl and 1-hydroxypyrazole). The tautomerism of 1-hydroxypyrazole has been ree xamined.