tert-butyl N-[5-methylsulfanyl-4-[3-[5-methyl-1-(2-trimethylsilylethoxymethyl)benzimidazol-4-yl]phenyl]sulfonylthiophene-2-carboximidoyl]carbamate → 4-[3-(5-Methyl-1H-benzoimidazol-4-yl)-benzenesulfonyl]-5-methylsulfanyl-thiophene-2-carboxamidine

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A solution of [Imino-(5-methylsulfanyl-4-{3-[5-methyl-1-(2-trimethylsilanyl-ethoxymethyl)-1H-benzoimidazol-4-yl]-benzenesulfonyl}-thiophen-2-yl)-methyl]-carbamic acid tert-butyl ester (14 mg, 0.021 mmol, Example 287: step c) in 1 mL of TFA was heated at 50° C. for 2 h under Ar, cooled to RT. Removal of the solvent under reduced pressure followed by flash chromatography of the residue on silica gel (10–15% MeOH/CH2Cl2) gave 14 mg (100%) of product as colorless oil: 1H-NMR (CD3OD; 400 MHz) δ 9.28 (s, 1H). 8.35 (s, 1H), 8.20 (d, 1H, J=7.6 Hz). 8.11 (s, 1H), 7.86 (dd, 1H, J=7.7, 7.7), 7.80 (m, 2H), 7.63 (d, 1H, J=8.6 Hz), 2.72 (s, 3H), 2.30 (s, 3H). Mass spectrum (ESI, m/z): Calcd. for C20H18N4O2S3, 443.1.00 (M+H), found 443.1.

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