Synthesis of deuterium and 15 N‐labelled 2,5‐ Bis [5‐amidino‐2‐pyridyl]furan and 2,5‐ Bis [5‐(methoxyamidino)‐2‐pyridyl]furan

The acetate salt of 2,5‐ bis [5‐amidino‐2‐pyridyl]furan‐ d 2 / 15 N 2 ( 4) was synthesized from 2,5‐ bis [5‐cyano‐2‐pyridyl]furan‐ d 2 ( 2 ), through the bis ‐ O ‐acetoxyamidoxime followed by hydrogenation. Compound 2 was obtained via a Stille coupling reaction of 6‐chloronicotinonitrile with 2,5‐ bis [tri‐ n ‐butyltin]‐furan‐ d 2 ( 1 ). 2,5‐ bis [5‐amidino‐2‐pyridyl)furan‐ d 6 ( 10) was synthesized from 2,5‐ bis [5‐cyano‐2‐pyridyl)furan‐ d 6 ( 9 ) via a direct reaction with lithium bis (trimethylsilyl)amide, followed by deprotection with ethanolic HCl. 15 N and/or deuterium‐labelled methoxy‐amidines 5a ‐ d 2 / 15 N 2 , 5b ‐ d 8 , 12 , 14 ‐ d 6 were prepared in good yield via direct methylation of their respective diamidoximes with either dimethylsulfate‐ d 0 or dimethylsulfate‐ d 6 in DMF solution and using LiOH as a base. Copyright © 2006 John Wiley & Sons, Ltd.