Process Development of the PDE4 Inhibitor K-34

…, T Taguchi, H Tsumuki, I Chujo, S Mohri

Index: Yanagisawa, Arata; Taga, Masashi; Atsumi, Toshiyuki; Nishimura, Koichiro; Ando, Kyoji; Taguchi, Tsuyoshi; Tsumuki, Hiroshi; Chujo, Iwao; Mohri, Shin-Ichiro Organic Process Research and Development, 2011 , vol. 15, # 2 p. 376 - 381

Full Text: HTML

Citation Number: 3

Abstract

A short and practical synthesis of the PDE4 inhibitor K-34 (1) was developed. This synthesis was achieved in four steps and with a 58% overall yield. The unique spiro acetal was created with exceptionally high yield by utilizing the neighbor carboxylic acid assistance. This synthesis also features efficient ketone construction with 4-pyridinylmethyl anion 9 and ester 18, in which overreaction should be prohibited by quick in situ enolate formation. ...