For some compounds, such as these, the names given have been widely used although the systematic names end in "-olinone". In view of this, the least hydrogenated forms should be named as
"4-oxopyrazole", "5-oxopyrazole", etc. The locant designates the position of the keto group.
This HTML reproduction of Sections A, B and C of IUPAC "Blue Book" is as close as possible to the
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Copyright 1979 IUPAC.] If you need to cite these rules please quote this reference as their source.
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