A Short and Efficient Synthesis of a Chiral Pyridazinone Derivative by the Chiral-Pool Method

Abstract

The asymmetric synthesis of a (R)-4,5-dihydro-5-methylpyridazin-3(2H)-one derivative bearing a pyrazolopyridine ring, which is a potent inhibitor of phosphodiesterase, was achieved with a high optical yield in four steps starting from (R)-2-chloropropionyl chloride by a chiral-pool method.