Reaction Steps
A solution of 2-amino-N-(2,4-dichloro-3-(((2-methoxy-1-(pyridin-2-ylmethyl)-1H-benzo[d]imidazol-4-yl)oxy)methyl)phenyl)-N-methylacetamide (0.45 g, 0.9 mmol) in anhydrous NMP (12 ml) was treated with HBTU (0.48 g, 1.2 mmol), 3-(4-(methoxycarbonyl)phenyl)propanoic acid (0.22 g, 1.08 mmol) and diisopropylethyl amine (0.47 mL, 2.7 mmol) with stirring at room temperature overnight. To the reaction was added ethyl acetate (100 mL) and the mixture was washed with aqueous saturated sodium bicarbonate (100 mL×3). The organic layer was dried over magnesium sulfate, filtered and evaporated to a yellow residue, 0.59 g that was purified by chromatography (silica gel, ethyl acetate and methanol gradient) to afford methyl 4-(3-(2-((2,4-dichloro-3-((2-methoxy-1-(pyridin-2-ylmethyl)-1H-benzo[d]imidazol-4-yloxy)methyl)phenyl)(methyl)amino)-2-oxoethylamino)-3-oxopropyl)benzoate (37) as a white solid, 0.18 g (29%), LC/MS (+APCI) m/z 690 (M++1) and 704 (M++1), 1HNMR (400 MHz, CDCl3) δ 8.60 (m, 1H), 7.92 (m, 2 H), 7.60 (m, 1H), 7.49 (m, 1H), 7.29 (m, 1H), 7.19 (m, 1H), 7.02 (m, 1H), 6.91 (m, 1H), 6.82 (m, 2H), 6.35 (m, 1H), 5.67 (s, 2H), 5.28 (s, 2H), 4.21 (s, 3H), 3.89 (s, 3H), 4.1 to 2.5 (many multiplets, 10H). 13CNMR (100 MHz, CDCl3) δ 171.4, 168.2, 156.1, 149.6, 149.0, 146.2, 138.4, 138.1, 137.0, 135.8, 135.3, 130.2, 129.9, 128.4, 128.2, 122.6, 121.7, 120.8, 107.3, 103.0, 67.0, 57.5, 51.9, 47.7, 41.9, 37.4, 35.9, 31.4
