Reaction Steps
To a vial containing the title compound of Example 3 Step D (300 mg, 0.78 mmol), were added 3-bromo iodobenzene (0.120 mL, 0.94 mmol), copper iodide (11.0 mg, 0.078 mmol), potassium phosphate (349 mg, 1.64 mmol), and 1,2-trans-N,N-dimethylcyclohexane diamine (0.049 mL, 0.31 mmol). The reaction mixture was placed under a nitrogen atmosphere, and anhydrous toluene (1.0 mL, deoxygenated via nitrogen sparge), was added. The vial was then capped and placed in a pre-heated oil bath (110° C.) and stirred rapidly for 20 h. The mixture was then allowed to cool to room temperature, then was filtered through a silica gel plug, eluting with EtOAc. The filtrate was concentrated in vacuo: LCMS B, tr=3.11 min, m/z 540.0 [M+H]+. The crude adduct was dissolved in 1,4-dioxane (4 mL). 2 N aq. LiOH (3.9 mL, 7.8 mmol) was added, and the resultant mixture was stirred at 50° C. for 4 h. The mixture was allowed to cool to room temperature whereupon it was quenched by the addition of 2 N aq. HCl. The aqueous phase was extracted with EtOAc, and the organic phase was dried over Na2SO4 and concentrated in vacuo. To the crude carboxylic acid obtained above were added EDC (450 mg, 2.36 mmol), HOBt (317 mg, 2.36 mmol), and β-alanine tert-butyl ester hydrochloride (426 mg, 2.36 mmol). The resultant mixture was dissolved in DMF (4 mL), DIEA (1.36 mL, 7.69 mmol) was added, and the reaction mixture was stirred at 50° C. for 18 h. The reaction mixture was quenched by addition of sat. aq. NH4Cl, and the aqueous phase was extracted with EtOAc. The organic phase was concentrated in vacuo. Purification by flash chromatography on silica gel (0 to 50%, then 50 to 100% EtOAc in hexanes) provided the title compound: LCMS A, tr=4.48 min, m/z 597.3 [M−tBu+H]+; 1H NMR (500 MHz, CDCl3) δ 7.67-7.64 (m, 4H), 7.59 (d, J=9.0 Hz, 1H), 7.39-7.35 (m, 1H), 7.24-7.20 (m, 5H), 6.95 (d, J=9.0 Hz, 1H), 6.81-6.79 (m, 1H), 3.64 (q, J=6.0 Hz, 2H), 3.63-3.56 (m, 1H), 3.05 (dd, J=13.5, 9.0 Hz, 1H), 2.80 (dd, J=13.5, 5.5 Hz, 1H), 2.52 (t, J=6.0 Hz, 2H), 1.79-1.72 (m, 1H), 1.56-1.47 (m, 1H), 1.44 (s, 9H), 1.39-1.30 (m, 2H), 0.90 (t, J=7.0 Hz, 3H).
