Process Research and Large-Scale Synthesis of a Novel 5, 6-Dihydro-(9H)-pyrazolo [3, 4-c]-1, 2, 4-triazolo [4, 3-a] pyridine PDE-IV Inhibitor

…, BG Anderson, SL Orrill, PJ Daniels

Index: Urban, Frank J.; Anderson, Bruce G.; Orrill, Susan L.; Daniels, Peter J. Organic Process Research and Development, 2001 , vol. 5, # 6 p. 575 - 580

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Citation Number: 23

Abstract

An efficient synthesis of the PDE IV inhibitor, 9H-cyclopentyl-7-ethyl-3-(thiophen-2-yl)- pyrazolo [3, 4-c]-1, 2, 4-triazolo-5, 6-dihydro-[4, 3-a] pyridine 1 is described. Starting from commercially available γ-caprolactone, the synthesis was carried out in 10 steps. Key transformations were the selective O-methylation of diketone, 3-hydroxy-1-(4- methoxybenzyl)-4-propionyl-5, 6-dihydro-1H-pyridin-2-one, with dimethyl sulfate and ...