合成路线1

The known amino tetralone (I) was coupled with 4-cyano-2-fluorobenzoic acid (II) in the presence of EDC to give amide (III). Subsequent conversion of the nitrile group of (III) into the required amidine was achieved by the following sequence consisting of addition of SH2, followed by S-methylation to produce the iminothioether (IV), displacement of the methylthio group of (IV) with ammonium acetate, and then protection of the resulting amidine with di-tert-butyl dicarbonate, yielding the Boc-protected amidine (V). Basic hydrolysis of the ethyl ester group of (V) generated the corresponding carboxylic acid (VI). Finally, the Boc protecting group of (VI) was cleaved by means of trifluoroacetic acid.