合成路线1

BCX-34 is synthesized from 3-pyridylcarboxaldehyde in ten steps in 10% overall yield as described by Montgomery et al. and depicted in Scheme 19337601a. The reaction of (I) with cyanoacetic acid followed by sodium borohydride reduction of the substituted acrylonitrile intermediate gave (II) in good yield. A key step in the synthesis is the formation of aldehyde (III) using sodium hydride and ethyl formate. The enamine (IV) is then prepared from (III) and glycine methyl ester hydrochloride buffered with sodium acetate. Protection of the enamine nitrogen of (IV) is required to yield (V) before cyclization to pyrrole (VI) is carried out using 1,5-diazabicyclo[4.3.0]non-5-ene (DBN). This reaction gives a mixture of (VI) and (VII) as products and the mixture is all converted to (VII) by sodium carbonate hydrolysis before isolation of solid (VII). The cyclization of the pyrimidine ring portion of BCX-34 is accomplished in three steps from (VII) through a sequence first described by Yamazaki et al. A study of the reaction conditions for the final cyclization step of the synthesis of Peldesine described in scheme 19337601a, in order to improve the yield of the target compound, and to minimize the side products, is presented in Org Proc Res Develop 2000, 4: 129.