反应详情

2-Fluoro-2-methylpropyl trifluoromethanesulfonate (obtained as described in Example 1, preparation of starting materials) (679 mg, 3.03 mmol) was added to a solution of (E)-methyl 3-(4-(3,3-dimethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)-3,5-difluorophenyl)acrylate (obtained as described in Example 5, preparation of starting materials) (600 mg, 1.51 mmol) and N-ethyl-N-isopropylpropan-2-amine (0.915 ml, 5.30 mmol) in 1,4-dioxane (2.5 ml). The reaction was stirred at room temperature for 1 h. The reaction was then heated to 105° C. for 88 hours. The volatiles were removed under vacuum and the crude product was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in heptane. Pure fractions were evaporated to dryness to afford (E)-methyl 3-(3,5-difluoro-4-(2-(2-fluoro-2-methylpropyl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl)acrylate (430 mg, 60.4%) as a white solid. The racemic product was purified by preparative HPLC (Chiralpak AD column, 20 μm silica, 50 mm diameter, 250 mm length), Heptane:Ethanol 90:10 90 ml/min. Fractions containing the desired compounds were evaporated to dryness to afford (E)-methyl 3-(3,5-difluoro-4-(2-(2-fluoro-2-methylpropyl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl)acrylate (isomer 1, first eluted, 149 mg, 34.6%) and (E)-methyl 3-(3,5-difluoro-4-(2-(2-fluoro-2-methylpropyl)-3,3-dimethyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl)acrylate (isomer 2, second eluted, 143 mg, 33.3%) as cream coloured solids. 1H NMR (400 MHz, CDCl3, 30° C.) δ 1.01 (3H, d), 1.08 (3H, s), 1.15 (3H, d), 1.34 (3H, s), 2.55 (1H, dd), 2.66 (1H, d), 2.98-3.06 (1H, m), 3.17 (1H, dd), 3.80 (3H, s), 5.23 (1H, s), 6.38 (1H, d), 6.97 (2H, d), 7.07-7.12 (2H, m), 7.17-7.22 (1H, m), 7.32 (1H, s), 7.46-7.5 (1H, m), 7.52 (1H, d). m/z ES− [M−H]− 469.

1. temperatureThe reaction was then heated to 105° C. for 88 hours
2. customThe volatiles were removed under vacuum
3. customthe crude product was purified by flash silica chromatography, elution gradient 0 to 50% EtOAc in heptane
4. customPure fractions were evaporated to dryness