Dedicated to the memory of late Professor Ferenc Fülöp (1952–2021)
Abstract
A new, efficient process for the synthesis of 5-acetyl-1H-pyrazole-3-carboxylic acid, a versatile building block and the key intermediate of
darolutamide, using diethyl pyrazole-3,5-dicarboxylate as the starting material is
described. Contrary to the synthetic routes known from the literature, this procedure
does not employ explosive diazo reagents, moreover it is simple and safe, thereby
suitable for scale-up.
Keywords
ester hydrolysis - regioselectivity - drug substance - key intermediate - safety -
scalability