Practical and Scalable Synthesis of a Selective CCK1 Receptor Antagonist

We describe a practical and scalable route to compound (Z)-1, a selective CCK1 receptor antagonist Notable features of this concise route are (1) a regioselective construction of the pyrazole core through the reaction of an aryl hydrazine and an elaborated acetylenic ketone, (2) a Tf2O/pyridine mediated Z-selective dehydration of an alpha-hydroxyester, and (3) a stereoselective hydrolysis The sequence is high-yielding and amenable for large-scale synthesis