* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With dimethyl sulfoxide; 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione In ethyl acetateInert atmosphere
Synthesis Example 19; Synthesis of N-substituted aniline intermediate XII; The purchased N-Boc-2-piperidine methanol (1.4 g, 1 eq.) was dissolved in ethyl acetate (50 mL) and charged with 2-iodoxybenzoic acid (3.4 g, 1.1 eq.). The resulting slurry was stirred under inert atmosphere and DMSO (781 μL, 2.2 eq.) was added via syringe and the reaction was stirred overnight. Solid material was removed by filtration and the filtrate washed with 10percent NaS2O3/saturated NaHCO3 (1:1, 3.x.20 mL), water (1.x.20 mL) and brine (1.x.20 mL). The organic layer was then removed in vacuo to afford 1.3 g of the aldehyde (94percent yield). Coupling was then achieved by dissolving the aldehyde (1.1 g, 1 eq.) and 4-fluoroaniline (481 μL, 1 eq.) in dichoroethane (20 mL). Under an inert atmosphere NaBH(OAc)3 (1.5 g, 1.4 eq.) and concentrated acetic acid (294 μL, 1 eq.) were added and the reaction was monitored by TLC and LC-MS. The mixture was diluted with ethyl acetate and washed with 10percent citric acid (.x.3), brine (x1) and dried over magnesium sulfate. The mixture was filtered and the solvent removed by rotary evaporation and dried in vacuo to afford 1.4 g of the intermediate XII secondary aniline (90percent yield). ESI-MS m/z=309.1 [M+H]+.
94%
With 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione In dimethyl sulfoxide; ethyl acetateInert atmosphere
Synthesis Examples 19 Synthesis of N-substituted aniline intermediate XII The purchased N-Boc-2-piperidine methanol (1.4 g, 1 eq.) was dissolved in ethyl acetate (50 mL) and charged with 2-iodoxybenzoic acid (3.4 g, 1.1 eq.). The resulting slurry was stirred under inert atmosphere and DMSO (781 μL, 2.2 eq.) was added via syringe and the reaction was stirred overnight. Solid material was removed by filtration and the filtrate washed with 10percent NaS2O3/ saturated NaHCO3 (1:1,3 x 20 mL), water (1 x 20 mL) and brine (1 x 20 mL). The organic layer was then removed in vacuo to afford 1.3 g of the aldehyde (94percent yield). Coupling was then achieved by dissolving the aldehyde (1,1 g, 1 eq.) and 4-fluoroaniline (481 μL, 1 eq.) in dichoroethane (20 mL). Under an inert atmosphere NaBH(OAc)3 (1.5 g, 1.4 eq.) and concentrated acetic acid (294 μL, 1 eq.) were added and the reaction was monitored by TLC and LC-MS. The mixture was diluted with ethyl acetate and washed with 10percent citric acid (x 3), brine (x 1) and dried over magnesium sulfate. The mixture was filtered and the solvent remove by rotary evaporation and dried in vacuo to afford 1.4 g of the intermediate XII secondary aniline (90percent yield). ESI-MS m/z= 309.1 [M+H]+.
78%
With Dess-Martin periodane In dichloromethane at 20℃; for 1.5 h;
Step I (2): Preparation of tert-butyl 2-formylpiperidine-1-carboxylate. To a solution of tert-butyl 2-(hydroxymethyl)piperidine-1-carboxylate (Step I (1), 1.80 g, 8.4 mmol) in dichloromethane was added Dess-Martin reagent (15 wt percent in dichloromethane, 4.6 g, 27.3 mmol). The mixture was stirred at rt for 1.5 h. The mixture was then concentrated in vacuo and purified by silica gel Flash Chromatography to give 1.4 g of the title compound (78percent yield): 1H NMR (CDCl3, 500 MHz) δ 1.23-1.33 (1H, m), 1.38-1.46 (9H, m), 1.54-1.69 (4H, m), 2.92 (1H, m), 3.88-4.08 (1H, m), 4.47-4.61 (1H, m), 9.58 (1H, s).
73%
With oxalyl dichloride; dimethyl sulfoxide In dichloromethane at -78 - 20℃; for 0.583333 h;
Example 11; 2-Formyl-piperidine-l-carboxylic acid tert-butyl ester; DMSO (7.14 mL, 98 mmol) was added drop-wise to a stirred solution of oxalyl chloride (30 mL, 2M in CH2Cl2, 60 mmol) in CH2C12 (60 mL) at-78°C. After 5 minutes, a solution of 2-hydroxymethyl-piperidine-1-carboxylic acid tert-butyl ester in CH2Cl2 (25 mL) was added and the reaction mixture as stirred at-78°C for 0.5 hours after which Et3N (25 mL, 181 mmol) was and the mixture allowed to warm slowly to room temperature with stirring. The mixture was then poured into water (100 mL) and the organic layer was separated. The organic extract was then washed with NaHCO3 (saturated). The aqueous phase was extracted with dichloromethane (3X30 mL). The combined organic phase was washed with water (30 mL) and brine (30 mL), dried (sodium sulfate), filtered and concentrated in vacuo. Chromatography gave the title product as a yellow oil (3.27 g, 73percent).
70%
With 4-methylmorpholine N-oxide In dichloromethane at 20℃; for 3 h;
[0145] To a solution of 2-piperidinemethanol (561 mg, 4.9 mmol) in dry THF (10 mL) was added di-tert-butyl dicarbonate (1.14 g, 5.2 mmol) and the mixture stirred overnight at room temperature. The reaction mixture was concentrated in vacuo to afford a colourless oil which was used in the next step without any further purification. [0146] To a stirred solution of 2-hydroxymethyl-piperidine-1-carboxylic acid tert-butyl ester (0.737 g, 3.4 mmol) in dry CH2Cl2 (10 mL) was added 3 A molecular sieves (1.03 g), N-methylmorpholine N-oxide (0.644 g, 5.5 mmol), and tetrapropylammonium perruthenate (72 mg, 0.21 mmol) and the mixture stirred at room temperature for 3 h. The reaction mixture was purified through a silica gel plug (Hexanes/EtOAc, 70:30 followed by 100:0) to afford the title aldehyde (0.500 g, 70percent) as a pale yellow oil. [0147] Using General Procedure B: To a stirred solution of 2-formyl-piperidine-1-carboxylic acid tert-butyl ester (0.163 g, 0.76 mmol) in dry CH2Cl2 (3.5 mL) was added (1H-benzimidazol-2-ylmethyl)-(5,6,7,8-tetrahydro-quinolin-8-yl)-amine (0.210 g, 0.76 mmol) and sodium triacetoxyborohydride (0.240 g, 1.1 mmol) and the mixture stirred overnight at room temperature. Purification by column chromatography on silica gel (CH2Cl2/MeOH, 98:2 followed by 96:4) gave a pale yellow foam containing a mixture of diastereomers (0.305 g). [0148] To a stirred solution of the diastereomers (0.305 g) in dry CH2Cl2 (2 mL) was added trifluoroacetic acid (1 mL) dropwise and the mixture stirred at room temperature for 3.5 h. The reaction mixture was diluted with CH2Cl2 (10 mL) and then concentrated in vacuo. The concentrate was diluted with CH2Cl2 (20 mL) and extracted with 1N NaOH (30 mL). The aqueous layer was washed with CH2Cl2 (2.x.15 mL) and then the combined organic layers were dried (Na2SO4), filtered, and concentrated in vacuo. Purification and separation of the two diastereomers by radial chromatography on a 1 mm TLC grade silica gel plate (CH2Cl2/MeOH/NH4OH, 100:1:1 followed by 50:1:1) afforded a less polar diastereomer (63 mg, 22percent) and a more polar one (22 mg, 8percent) (stereochemistry unknown), both as colourless oils. [0149] Using General Procedure D: Conversion of the less polar distereomer from above (63 mg, 0.17 mmol) to the hydrobromide salt gave COMPOUND 3 (83 mg) as a white solid. 1H NMR (D2O) δ 1.34-1.68 (m, 3H), 1.73-1.93 (m, 3H), 1.93-2.08 (m, 2H), 2.08-2.23 (m, 1H), 2.24-2.38 (m, 1H), 2.79 (dd, 11H, J=14.7, 9.9 Hz), 2.94-3.07 (m, 3H), 3.27 (dd, 1H, J=14.7, 9.9 Hz), 3.38-3.56 (m, 2H), 4.33 (s, 2H), 4.57 (dd, 1H, J=9.9, 5.7 Hz), 7.56-7.62 (m, 2H), 7.70-7.83 (m, 3H), 8.28 (d, 1H, J=7.8 Hz), 8.57 (d, 1H, J=4.8 Hz); 13C NMR (D2O) δ 19.84, 20.28, 21.76, 22.16, 26.99, 27.83, 45.34, 47.01, 54.30, 54.82, 58.86, 114.55, 125.99, 127.08, 131.59, 140.23, 141.046, 147.96, 149.03, 149.84; ES-MS m/z 376 (M+H); Anal. Calcd. for C23H29N5.3.0HBr.1.2H2O.0.3C4H10O: C, 43.90; H, 5.69; N, 10.58; Br, 36.20. Found: C, 43.78; H, 5.47; N, 10.54; Br, 36.41.
56%
With pyridinium chlorochromate In dichloromethane at 20℃; for 2 h;
2-Hydroxymethyl-piperidine-l-carboxylic acid butyl ester (1.0 g, 4.65 mmol) (Example 30) was taken in dichloromethane. Celite and pyridinium chlorochromate (2.0 g, 9.30 mmol) was added to it. The reaction mixture was stirred at room temperature for about 2 hours. The reaction mixture was filtered through a celite pad. The filtrate was then concentrated to yield the title compound.Yield: 0.55 g (56percent).
0.8 kg
With sodium hypochlorite; 2,2,6,6-Tetramethyl-1-piperidinyloxy free radical; sodium hydrogencarbonate; sodium bromide In dichloromethane; water at 0 - 5℃; Large scale
Example 2 tert-butyl 2-formylpiperidine- 1-carboxylate Tert-butyl 2-(hydroxymethyl)piperidine-l-carboxylate (1.0 kg, 4.6 mol), 2,2,6,6- Tetramethyl-l-piperidinyloxy, free radical, 2,2,6, 6-Tetramethylpiperidine 1-oxyl (TEMPO, Sigma-Aldrich 214000, CAS Reg No. 2564-83-2, Geisslmeir, David; et al. (2005) Monatsh. Chem 136(9), 1591-1599, 1.45 g, 9.29 mmol), NaBr (48 g, 0.46 mol) and NaHC03 (0.98 kg, 11.6 mol) in H20 (5 L) and DCM (5 L) were cooled to 0-5 °C. 10percent NaOCl (6.22 kg, 8.36 mol) was added dropwise at 0-5 °C. After addition, the mixture was stirred at 0-5 °C for 30 min. After reaction completed, the organic layer was separated and charged into another Reactor. 10 percent Na2S03 was added dropwise to the organic layer to Kl-starch paper indicating negative. The organic layer was separated, filtered, washed with H20 and brine and dried over Na2S04. The solvent was removed under vacuum. 0.8 kg of tert-butyl 2- formylpiperidine-l-carboxylate was obtained as an orange oil. (Assay Yield 80 percent). 1H NMR (400 MHz, CDC13) δ ppm 9.59 (br s, IH), 4.38-4.71 (m, IH), 3.78-4.10 (brm, IH), 2.73- 3.82 (brm, IH), 2.11-2.21 (m, IH), 1.57-1.71(m, 3H), 1.30-1.71 (m, 10H), 1.26 (brs, IH); 13C NMR (100 MHz, CDC13) δ ppm 201.3, 158.6, 80.3, 75.1, 65.3, 61.5, 60.6, 43.0, 41.9, 28.4, 28.3, 25.3, 24.7, 23.5, 20.9, 19.2; IR (neat) 2983, 1694, 1681, 1210 cm"1
Reference：
[1] Tetrahedron, 2005, vol. 61, # 10, p. 2631 - 2643
[2] Organic Letters, 1999, vol. 1, # 4, p. 667 - 670
[3] Patent: US2010/210593, 2010, A1, . Location in patent: Page/Page column 48
[4] Patent: EP2942346, 2015, A1, . Location in patent: Paragraph 0173
[5] Tetrahedron Letters, 1996, vol. 37, # 13, p. 2165 - 2168
[6] Journal of Organic Chemistry, 1996, vol. 61, # 17, p. 6040 - 6043
[7] Angewandte Chemie - International Edition, 2016, vol. 55, # 41, p. 12881 - 12885[8] Angew. Chem., 2016, vol. 128, # 41, p. 13073 - 13077,5
[9] Patent: US2006/46984, 2006, A1, . Location in patent: Page/Page column 23
[10] Patent: WO2005/80386, 2005, A1, . Location in patent: Page/Page column 41
[11] Bulletin of the Korean Chemical Society, 2011, vol. 32, # 7, p. 2449 - 2452
[12] Patent: US2003/220341, 2003, A1, . Location in patent: Page/Page column 12-13
[13] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 19, p. 4861 - 4866
[14] Synthetic Communications, 2009, vol. 39, # 20, p. 3611 - 3620
[15] Patent: WO2006/117653, 2006, A1, . Location in patent: Page/Page column 60
[16] Journal of the American Chemical Society, 1999, vol. 121, # 4, p. 700 - 709
[17] Tetrahedron Letters, 2000, vol. 41, # 51, p. 10131 - 10134
[18] Bioorganic and medicinal chemistry letters, 2002, vol. 12, # 13, p. 1785 - 1789
[19] Journal of the Chemical Society. Perkin Transactions 1, 2002, # 12, p. 1438 - 1443
[20] Tetrahedron Letters, 2002, vol. 43, # 48, p. 8759 - 8763
[21] Bioorganic and Medicinal Chemistry Letters, 2003, vol. 13, # 21, p. 3847 - 3851
[22] Patent: WO2007/30761, 2007, A2, . Location in patent: Page/Page column 49; 144-145
[23] Journal of Organic Chemistry, 2010, vol. 75, # 20, p. 6793 - 6805
[24] Patent: WO2016/66490, 2016, A1, . Location in patent: Page/Page column 14-15
[25] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 17, p. 4539 - 4544
2
[ 211310-10-0 ]
[ 157634-02-1 ]
Yield
Reaction Conditions
Operation in experiment
94%
Stage #1: With lithium aluminium tetrahydride In tetrahydrofuran at 0℃; for 0.666667 h; Stage #2: With water In tetrahydrofuran; ethyl acetate
2-Formyl-piperidine-l-carboxylic acid tert-butyl ester (Intermediate B) 2-(Methoxy-methyl-carbamoyl)-piperidine-l-carboxylic acid tert-butyl ester(Intermediate A) (5.0 g, 18.5 mmol) was dissolved in anhydrous THF (45 ml) and under nitrogen LAH (0.7 g, 18.5 mmol) was added to the stirred solution at 0 °C in 10 minutes. The reaction mixture was stirred at 0 0C for 30 minutes, then ethyl acetate (25 ml) and water (25 ml) were added. The phases were separated, the aqueous phase was extracted twice with ethyl acetate (25 ml) and the combined organic layers were washed once with 1 N aqueous sulphuric acid and twice with brine. The solution was dried and concentrated to yield 3.7 g (94 percent) of the title compound as an oil.
Reference：
[1] Patent: WO2007/39782, 2007, A1, . Location in patent: Page/Page column 24
[2] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 15, p. 4013 - 4017
[3] Patent: EP1593681, 2005, A1, . Location in patent: Page/Page column 43-44
[4] Bioorganic and Medicinal Chemistry Letters, 2010, vol. 20, # 12, p. 3737 - 3741
3
[ 4043-87-2 ]
[ 157634-02-1 ]
Reference：
[1] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 15, p. 4013 - 4017
[2] Tetrahedron Letters, 2002, vol. 43, # 48, p. 8759 - 8763
[3] Tetrahedron Letters, 2000, vol. 41, # 51, p. 10131 - 10134
[4] Journal of the American Chemical Society, 1999, vol. 121, # 4, p. 700 - 709
[5] Journal of Organic Chemistry, 1991, vol. 56, # 8, p. 2775 - 2781
4
[ 75844-69-8 ]
[ 157634-02-1 ]
Yield
Reaction Conditions
Operation in experiment
67%
With sec-BuLi; N,N,N,N,-tetramethylethylenediamine In N,N-dimethyl-formamide
N-Boc-Piperidine-2-Carboxaldehyde A solution of N-Boc-Piperidine (6.0 g, 32.4 mmol) in ether (65 mL) was cooled to -60° C. and treated with TMEDA (4.9 mL, 32.4 mmol) followed by sec-BuLi (54.8 mL, 71.2 mmol) dropwise. The mixture was slowly warmed to -20° C. and stirred for 10 min and then cooled to -78° C. The mixture was treated with a solution of DMF (3.8 mL, 48.6 mmol) in 6 mL of ether via syringe, stirred for 10 min, and then quenched with 60 mL saturated ammonium chloride solution. The mixture was warmed to room temperature, and the organic layer was separated. The aqueous layer was extracted three times with ether, and the combined extracts were dried over K2CO3. The organic layer was concentrated to give a crude product as an orange oil. Purification by column chomatography on silica gel with hexanes:EtOAc (4: 1) afforded 4.2 g (67percent) of the product as a clear oil which was homogeneous by TLC analysis. 1H NMR (300 MHz) δ9.58 (s, 1 H), 4.69-4.51 (br. m, 1 H), 4.12-3.85 (br. m, 1 H), 2.85 (br. s, 1 H), 2.19-2.13 (d, 1 H), 1.72-1.23 (m, 15 H); 13C NMR (75 MHz) 201.4 (s), 80.4 (s), 43.0 (br. s), 28.3 (s), 24.7 (s), 23.6 (s), 20.9 (s) ppm.
Reference：
[1] Patent: US6369078, 2002, B1,
5
[ 24424-99-5 ]
[ 157634-02-1 ]
Reference：
[1] Organic Letters, 1999, vol. 1, # 4, p. 667 - 670
[2] Tetrahedron Letters, 2002, vol. 43, # 48, p. 8759 - 8763
[3] Bioorganic and medicinal chemistry letters, 2002, vol. 12, # 13, p. 1785 - 1789
[4] Tetrahedron Letters, 2000, vol. 41, # 51, p. 10131 - 10134
[5] Journal of Organic Chemistry, 1993, vol. 58, # 5, p. 1109 - 1117
[6] Bulletin of the Korean Chemical Society, 2011, vol. 32, # 7, p. 2449 - 2452
[7] Patent: WO2006/117653, 2006, A1,
6
[ 3433-37-2 ]
[ 157634-02-1 ]
Reference：
[1] Organic Letters, 1999, vol. 1, # 4, p. 667 - 670
[2] Tetrahedron, 2005, vol. 61, # 10, p. 2631 - 2643
[3] Tetrahedron Letters, 2002, vol. 43, # 48, p. 8759 - 8763
[4] Bioorganic and medicinal chemistry letters, 2002, vol. 12, # 13, p. 1785 - 1789
[5] Journal of the American Chemical Society, 1999, vol. 121, # 4, p. 700 - 709
[6] Journal of Organic Chemistry, 1996, vol. 61, # 17, p. 6040 - 6043
[7] Bulletin of the Korean Chemical Society, 2011, vol. 32, # 7, p. 2449 - 2452
[8] Patent: WO2006/117653, 2006, A1,
7
[ 132910-79-3 ]
[ 157634-02-1 ]
Reference：
[1] Journal of Organic Chemistry, 1991, vol. 56, # 8, p. 2775 - 2781
[2] Journal of the Chemical Society. Perkin Transactions 1, 2002, # 12, p. 1438 - 1443
8
[ 98303-20-9 ]
[ 157634-02-1 ]
Reference：
[1] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 19, p. 4861 - 4866
[2] Bioorganic and Medicinal Chemistry Letters, 2004, vol. 14, # 15, p. 4013 - 4017
[3] Tetrahedron Letters, 1996, vol. 37, # 13, p. 2165 - 2168
9
[ 32559-18-5 ]
[ 157634-02-1 ]
Reference：
[1] Journal of Organic Chemistry, 1991, vol. 56, # 8, p. 2775 - 2781
10
[ 24608-52-4 ]
[ 157634-02-1 ]
Reference：
[1] Journal of Organic Chemistry, 1991, vol. 56, # 8, p. 2775 - 2781
11
[ 24424-99-5 ]
[ 3433-37-2 ]
[ 157634-02-1 ]
Reference：
[1] Patent: WO2016/66490, 2016, A1,
12
[ 75844-69-8 ]
[ 68-12-2 ]
[ 157634-02-1 ]
Reference：
[1] Journal of Organic Chemistry, 1993, vol. 58, # 5, p. 1109 - 1117
With tetrabutyl ammonium fluoride; In ethyl acetate;
EXAMPLE 7 STR50 (+-)-N-tert-Butoxycarbonyl-2-piperdinecarboxaldehyde (2.13 g, 10.0 mmol; Hassner, et al. Journal Of Organic Chemistry 1991, 56, 2775) was added to <strong>[79265-30-8]2-(trimethylsilyl)thiazole</strong> (2.03 g, 11.0 mmol) at room temperature under argon. The reaction mixture was stirred for 6 h, then diluted with anhydrous THF (100 mL) and 5 mL of 1.0M tetrabutylammonium fluoride/THF, stirred for another 40 min and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with saturated aqueous NaHCO3, dried (Na2 SO4) and concentrated in vacuo to give thiazole 7a, as a solid; FAB-MS m/z 299 (MH)+. STR51
tert-butyl 2-(((3,4-difluorophenyl)amino)methyl)piperidine-1-carboxylate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
81%
Stage #1: tert-butyl 2-formylpiperidine-1-carboxylate; 3,4-difluoroaniline In dichloromethane at 20℃; for 0.5h; Inert atmosphere;
Stage #2: With sodium tris(acetoxy)borohydride In dichloromethane at 20℃; Inert atmosphere;
1 tert-Butyl 2-(((3,4-difluorophenyl)amino)methyl)piperidine-1-carboxylate (5 Scheme 1)
General procedure: To a solution of N-Boc-piperidin-2-yl-formaldehyde 1 (0.8 g,3.75 mmol) in 15 mL of dry dichloromethane was added aniline(0.51 mL, 5.62 mmol) and the mixture was stirred at room temperaturefor 30 min. Sodium triacetoxyborohydride (1.19 g,5.62 mmol) was introduced in one portion, and the reaction mixturewas stirred at room temperature overnight. The reaction mixturewas diluted with dichloromethane (100 mL) and washed with25 mL of aqueous potassium carbonate (2 25 mL) followed bybrine (50 mL) and dried over anhydrous sodium sulfate. After thesolvent was removed, the resultant oily residue was purified by aflash column chromatography (hexane/ethyl acetate) to affordtert-butyl 2-((phenylamino)methyl)piperidine-1-carboxylate 4 asa white colour solid (0.8 g, 80%)
tert-Butyl 2-((2-bromoquinolin-4-yl) (hydroxy)methyl)piperidine-1-carboxylate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
58%
In tetrahydrofuran; n-heptane;
tert-Butyl 2-((2-bromoquinolin-4-yl) (hydroxy)methyl)piperidine-1-carboxylate (intermediate 24) 2,4-Dibromoquinoline (500 mg, 1.74 mmol) was dissolved in dry THF (6 mL). i-PrMgCl LiCl (1.47 mL, 1.3M, 1.9 mmol) was added slowly, dropwise, at room temperature followed by the addition of N-boc piperidine-2-aldehyde (483.1 mg, 2.27 mmol). The mixture was stirred for 4 hrs checking the consumption of the magnesium reagent by LC-MS analysis. After the reaction was complete, sat. NH4Cl solution was added and the mixture was extracted three times with EtOAc. The solvent was evaporated and the product was purified by flash chromatography (EtOAc/heptane=1/4) and trituration in heptane to yield the intermediate 24 (474 mg, 58%) as a white solid. 1H NMR (CDCl3, 400 MHz): delta 8.22 (dd, J=8.5, 0.9 Hz, 1H), 7.97 (dd, J=8.6, 0.8 Hz, 1H), 7.62-7.73 (m, 2H), 7.55 (ddd, J=8.3, 6.9, 1.4 Hz, 1H), 5.66 (t, J=4.5 Hz, 1H), 4.31 (q, J=5.1 Hz, 1H), 3.83 (d, J=13.1 Hz, 1H), 3.71 (br. s., 1H), 3.19 (ddd, J=14.3, 13.1, 4.0 Hz, 1H), 1.87-1.98 (m, 1H), 1.77 (tt, J=9.5, 4.5 Hz, 1H), 1.59 (tt, J=8.1, 4.0 Hz, 1H), 1.42-1.54 (m, 2H), 1.21-1.41 ppm (m, 10H).
tert-butyl 2-((benzyl-(2-hydroxyethyl)amino)methyl)piperidine-1-carboxylate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
71%
Stage #1: tert-butyl 2-formylpiperidine-1-carboxylate; N-Benzylethanolamine With acetic acid In tetrahydrofuran at 20℃; for 0.166667h;
Stage #2: With sodium tris(acetoxy)borohydride In tetrahydrofuran at 20℃;
1A Example 1A: tert-butyl 2-((benzyl(2-hydroxyethyl)amino)methyl)piperidine-1-carboxylate
1-N-Boc-2-Piperidinecarbaldehyde (2 g, 9.3 mmol) was dissolved in THF (200 mL), and acetic acid (2.4 mL), and 2-benzylaminoethanol (1.6g, 10 mmol, 1.2 eq.) were added. After 10 minutes at room temperature, sodium triacetoxyborohydride was added and the solution was stirred overnight. Saturated aqueous NaHC03(300 mL) and ethyl acetate (500 mL) were added and the layers were separated. The organic layer was dried (MgS04) and the solvent was removed under reduced pressure. The residue was purified by silica chromatography (0-10% MeOH-DCM) to give the product as a colourless oil (2.33g, 71 %. LC-MS Method B (Basic); Rt = 1.60, m/z 349.2 (MH+).
71%
Stage #1: tert-butyl 2-formylpiperidine-1-carboxylate; N-Benzylethanolamine With acetic acid In tetrahydrofuran at 20℃; for 0.166667h;
Stage #2: With sodium tris(acetoxy)borohydride In tetrahydrofuran
1.1A Example 1A: tert-Butyl 2-((benzyl(2-hydroxyethyl)amino)methyl)piperidine-1- carboxylate (1) Boc Boc
1-//-Boc-2-Piperidinecarbaldehyde (2 g, 9.3 mmol) was dissolved in THF (200 mL), and acetic acid (2.4 mL), and 2-benzylaminoethanol (1.6g, 10 mmol, 1.2 eq.) were added. After 10 minutes at room temperature, sodium triacetoxyborohydride was added and the solution was stirred overnight. Saturated aqueous NaHC03 (300 mL) and ethyl acetate (500 mL) were added and the layers were separated. The organic layer was dried (MgS04) and the solvent was removed under reduced pressure. The residue was purified by silica chromatography (0-10% MeOH-DCM) to give the product as a colourless oil (2.33g,71 %. LC-MS Method B (Basic); Rt = 1.60, m/z 349.2 (MH+).
tert-butyl 2-(4-methyl-5-phenyl-1H-imidazol-2-yl)piperidine-1-carboxylate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
63%
Stage #1: tert-butyl 2-formylpiperidine-1-carboxylate With 1,4-diaza-bicyclo[2.2.2]octane In butan-1-ol for 0.166667h;
Stage #2: 1-Phenylpropane-1,2-dione With ammonium acetate In butan-1-ol at 60 - 65℃;
175a Example 175a: tert-butyl 2-(4-methyl-5-phenyl-1H-imidazol-2-yl)piperidine-1- carboxylate:
A solution of tert-butyl 2-formylpiperidine-1-carboxylate (1.0 g, 4.69 mmol) and DABCO (0.040 mg, 0.32 mmol) in n-butanol (25 mL) was stirred for 10 min, then NH4OAc (1.8 g, 23.44 mmol) was added and followed by 1-phenylpropane-1,2-dione (0.69 mg, 4.69 mmol) was added, and a mixture was heated to 60-65 °C and stirred for overnight. After the solution was cooled to rt., diluted NaHCO3solution was added, extracted with Ethyl Acetate (50 mL*3) and the organic phase was concentrated. The residue was purifed by column chromatography (hexane:MTBE=3:1) to get tert-butyl 2- (4-methyl-5-phenyl-1H-imidazol-2-yl)piperidine-1-carboxylate (1.0 g, yield: 63 %) of product as white solid. GC/MS (EI): m/z (%): 341 (8) [M+], 285 (14), 240 (35), 185 (100),172 (18), 159 (6), 117 (6), 103 (8), 73 (18).
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Material Science
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110K+ Compounds
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