ABSTRACT
Concise and efficient methods for the preparation of 3-substituted 4-ethoxycarbonylpyrazolin-5-ones are described. The synthetic strategies involve carbon-acylation in the presence of base, followed by ring cyclization with hydrazine or hydrazine monohydrochloride.
ACKNOWLEDGMENT
This publication was supported by Grant/Cooperative Agreement Number UR3/CCU418652 from The Centers for Disease Control and Prevention (CDC).