| 72% |
With trimethylsilyl trifluoromethanesulfonate; In dichloromethane; at 0 - 20℃; for 3h;Inert atmosphere; |
Step D: 1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]piperazine Into a 100 mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of tert-butyl 4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]piperazine-1-carboxylate (1.6 g, 4.12 mmol, 1.00 equiv) in dichloromethane (40 mL), followed by the addition of TMSOTf (1.5 g, 6.75 mmol, 1.60 equiv) dropwise with stirring at 0 C. To the above solution was added 6-dimethylpyridine (132.5 mg, 1.00 mmol, 0.30 equiv). The resulting solution was stirred for 3 hours at room temperature. The reaction was then quenched by the addition of 50 mL of saturated sodium bicarbonate aqueous. The resulting solution was extracted with ethyl acetate (30 mL*3). The combined organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied onto a silica gel column eluting with dichloromethane/methanol (10:1). This resulted in 854.0 mg (72%) of 1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]piperazine as off-white solid. LCMS (ES+): m/z 289.15 [M+H]+. |
| 72% |
With 2,6-dimethylpyridine; trimethylsilyl trifluoromethanesulfonate; In dichloromethane; at 0 - 20℃; for 3h;Inert atmosphere; |
Into a 100 mL round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of tert-butyl 4-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2- yl)phenyl]piperazine-1-carboxylate (1.6 g, 4.12 mmol, 1.00 equiv) in dichloromethane (40 mL), followed by the addition of TMSOTf (1.5 g, 6.75 mmol, 1.60 equiv) dropwise with stirring at 0 C. To the above solution was added 6-dimethylpyridine (132.5 mg, 1.00 mmol, 0.30 equiv). The resulting solution was stirred for 3 hours at room temperature. The reaction was then quenched by the addition of 50 mL of saturated sodium bicarbonate aqueous. The resulting solution was extracted with ethyl acetate (30 mL x 3). The combined organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was applied onto a silica gel column eluting with dichloromethane/methanol (10:1). This resulted in 854.0 mg (72%) of 1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]piperazine as off- white solid. LCMS (ES+): m/z 289.15 [M+H]+. |
|
With hydrogenchloride; In 1,4-dioxane; at 20℃; for 2h; |
Example 184; 2- {4- [4-(methylsulfonyl)piperazin-l-yl] phenyl}-4- [(3S)-piperidin-3~ylamino] thieno [3,2- c] py ridine-7-carboxamide; l-[4-(4,4,5,5-tetramethyl-l,3<2-dioxaborolan-2-yl)phenyllpiperazine; To tert-butyl 4- [4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl]piperazine-l-carboxylate (235 mg, 0.656 mmol) is added 5.0 mL of 4N HCl in dioxane and the resulting solution is stirred at rt for two hours whereupon the solution is concentrated under reduced pressure to afford the title compound as a white solid. 1H NMR δ 9.14 (br s, IH), 7.54 (d, 2H), 6.96 (d, 2H), 3.43 (m, 4H), 3.18 (m, 4H), 1.25 (s, 12H). |
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