文摘
A practical and scaleable synthesis of 2-chloro-5-(pyridin-2-yl)pyrimidine, an intermediate in the synthesis of a selectivePDE-V inhibitor, was developed. A Negishi cross-couplingbetween the in situ prepared 2-pyridylzinc chloride and 5-iodo-2-chloropyrimidine catalyzed by Pd(PPh3)4 afforded the productin one step. Development of a convenient purification did awaywith the necessity of chromatography, allowing the preparationof the product on kilogram scale.