[Synthesis]
The general steps for the synthesis of (R)-4-(2-(1H-indol-4-yl)-6-(1-(methylsulfonyl)cyclopropyl)pyrimidin-4-yl)-3-methylmorpholine from the compound (CAS:1233339-68-8) and 4-indolylboronic acid were as follows:
1. suspend bis(triphenylphosphine)palladium chloride (1.692 g, 2.41 mmol), (R)-4-(2-chloro-6-(1-(methylsulfonyl)cyclopropyl)pyrimidin-4-yl)-3-methylmorpholine (8.00 g, 24.11 mmol), 1H-indol-4-ylboronic acid (4.27 g 26.52 mmol) and 2M aqueous sodium carbonate (36.2 mL, 72.33 mmol) were heated to 90 °C for overnight reaction.
2. After the reaction was completed, the DME was removed and the reaction mixture was diluted with EtOAc (100 mL).
3. The mixture was washed with water (2 x 100 mL), the organic phase was separated, filtered through a diatomaceous earth pad and concentrated in vacuum to give the crude product.
4. Purify the crude product by silica gel column chromatography with an elution gradient of 0 to 10% EtOAc in DCM solution. The grades containing the target product were combined and the solvent was evaporated.
5. The residue was purified again by silica gel column chromatography with an elution gradient of 0 to 25% EtOAc in DCM solution. The fractions containing the target product were combined and the solvent was evaporated.
6. The residue is dissolved and purified by reversed-phase C18 silica gel column (415g HP C18 column) using a mixture of water (containing 1% NH3) and MeCN as the eluent with decreasing polarity. The grades containing the target product were combined and the solvent was evaporated.
7. The residue was dissolved in anhydrous MeOH, dried over MgSO4, filtered and the solvent evaporated to give a gel.
8. The colloid was dissolved in DCM (500 mL), filtered and the solvent was removed under reduced pressure.
9. The residue was dissolved in MeOH (50 mL), stirred overnight at room temperature, and the resulting precipitate was collected by filtration to afford the target product (R)-4-(2-(1H-indol-4-yl)-6-(1-(methylsulfonyl)cyclopropyl)pyrimidin-4-yl)-3-methylmorpholine (5.10 g, 51% yield).
Product characterization: 1H NMR (400 MHz, DMSO-d6) δ 1.29 (3H, d), 1.57-1.64 (2H, m), 1.68-1.78 (2H, m), 3.24-3.31 (1H, td), 3.29 (3H, s), 3.51 (1H, td), 3.67 (1H, dd), 3.80 (1H, d). d), 3.93-4.06 (1H, dd), 4.21 (1H, d), 4.61 (1H, bs), 6.85 (1H, s), 7.21 (1H, t), 7.32 (1H, t), 7.46 (1H, t), 7.56 (1H, d), 8.06 (1H, dd), 11.25 (1H, s); m/z (ESI+ ) MH+, 413.12. Chiral HPLC analysis (HPI 100 system on a 4,5 μm Chiralpak AS-H (250 mm × 4.6 mm) column, elution conditions: isohexane/EtOH/TEA 60/40/0.1) showed an Rf value of 8.815 and a purity of >99%. |