4-Fluorobenzo[b]thiophene

General procedure: A solution of 2, 6-difluorobenzaldehyde 7 (1.0g, 7.0mmol) and potassium carbonate (1.45g, 10.5mmol) in DMF (25mL) at 0C was added slowly with methyl thioglycolate (0.7mL, 7.7mmol) and the mixture was stirred at the same temperature for 30min. The reaction mixture was stirred at room temperature for 14h and then at 60C for 6h. Solvent was removed and the resulting residue was diluted with ethyl acetate (60mL) followed by washed with water (20mL). The organic layer was dried over Na2SO4, filtered, and concentrated to obtain a crude compound. The above crude compound (500mg, 2.38mmol) and potassium hydroxide (400mg, 7.14mmol) were taken into a mixture of EtOH/ water (12/2mL) and heated to reflux for 2h. The reaction mixture was cooled to room temperature and concentrated. The resulting residue was diluted with water (20mL), acidified with 6N HCl and extracted with ethyl acetate (60mL). The organic layer was dried over Na2SO4, filtered, and concentrated to afford colorless crystals. The resulting colorless crystals (1.0g, 5.1mmol) were mixed together with powdered copper (97mg, 1.53mmol) in quinoline (10mL) and heated at 185C for 2h. The reaction mixture was cooled to room temperature and diluted with ethyl acetate (60mL) and 2N HCl (20mL). The mixture was filtered and washed with ethyl acetate (50mL). The organic layer was dried over Na2SO4, filtered, and concentrated. The resulting crude product was purified by column chromatography using hexane to give colorless oil. To a solution of the above compound (1.0g, 6.57mmol) in dry THF (13mL) was added a 1.6M solution of n-BuLi in hexane (4.2mL, 6.57mmol) drop wise at-78C. The reaction mixture was stirred at same temperature for 30min and was added tri-n-butyltin chloride (1.79mL, 6.57mmol). The resulting solution was stirred for 1h at-78C and then at room temperature for another 1h. The reaction mixture was concentrated under reduced pressure and the resulting residue was diluted with ethyl acetate (60mL), washed with aqueous KF (2×20mL) and with water (2×20mL). The combined organic layers ware dried over MgSO4 and concentrated to obtain a crude product. A solution of the above crude compound (1.0g, 2.27mmol) and 2-bromopyridine (360mg, 2.27mmol) in toluene (22mL) was added with Pd(PPh3)4 (131mg, 0.114mmol). The reaction mixture was degassed thoroughly with nitrogen and stirred at 110C for 8h. After cooling to room temperature, the mixture was concentrated under reduced pressure. The obtained crude product was diluted with ethyl acetate, filtered through Celite, and washed with aqueous KF (2×15mL) followed by brine (15mL) and water (15mL). The organic layer was dried over MgSO4, filtered, and concentrated to afford a crude product which was purified by column chromatography using ethyl acetate/hexane (1:9) to afford the pure compound 8 as a white solid (260mg 40%).EXAMPLE 56 [0349] Preparation of (2S)-3-[(2R, 4R)-4-(4-Fluorobenzo[b]thiophen-2-yl)-2-methylpiperidinyl]-1-(1H-indol-4-yl)oxy-2-propanol oxalate. [CHEMMOL-00107] [0350] Preparation of N-t-Butoxycarbonyl-4-(4-fluorobenzo[b]thiophen-2-yl)-2-methyl-4-piperidinol. [0351] Scheme IA, Step A: To a solution of 4- and 6-fluorobenzo[b]thiophene (12.4 g, 81.7 mmol, prepared in example 55) in dry THF (415 mL) at -78 C. was added 1.6 M n-BuLi in hexanes (56.4 mL, 90.2 mmol). The solution was stirred at -78 C. for 1.5 h. N-t-butoxycarbonyl-2-methyl-4-piperidone (15.7 g, 73.5 mmol) dissolved in THF (40 mL) was added via a cannula at -78 C. The reaction mixture was stirred at -78 C. for 4 h. The reaction was then quenched with 300 mL of saturated aqueous NH4Cl solution. The mixture was extracted (2×500 mL) with EtOAc. The combined organic layers were then dried over MgSO4 and filtered. The filtrate was concentrated and purified by medium pressure chromatography (15% EtOAc/hexanes) to give the title compound as a white foam (3.66 g, 14%). 1HNMR (CDCl3) 7.54 (d, J=8.8 Hz, 1H), 7.25 (s, 1H), 7.22 (m, 1H), 6.96 (dd, J=9.0, 8.1, 1H), 4.31 (distt, 1H), 3.85 (m, 1H), 3.18 (dt, J=13.0, 2.9 Hz, 1H), 2.02-1.82 (m, 1H), 1.64 (dd, J=14.2, 6.8, 1H), 1.54-1.44 (m, 11H), 1.28 (d, J=6.8 Hz, 3H)Preparation of N-t-Butoxycarbonyl-4-(4-fluorobenzo[b]thiophen-2-yl)-4-piperidinol. [0342] Scheme IA, Step A: To a solution of 4- and 6-fluorobenzo[b]thiophene (1.70 g, 11.2 mmol) in dry THF (50 mL) at -78 C. was added 1.6 M n-BuLi in hexanes (9.08 mL, 14.5 mmol). The solution was stirred at -78 C. for 35 min. N-t-butoxycarbonyl-4-piperidone (2.67 g, 15.6 mmol) dissolved in THF (10 mL) was added via a cannula at -78 C. The reaction mixture was kept at -78 C. for 1.5 h, then allowed to warm to room temperature. The reaction was quenched with 150 mL of saturated aqueous NH4Cl solution. The mixture was then extracted (3×300 mL) with EtOAc. The combined organic layers were dried over MgSO4 and filtered. The filtrate was concentrated and purified by medium pressure chromatography (silica gel, 20% EtOAc/hexanes) to give the intermediate title compound as a white foam (0.525 g, 13%). IR (CHCl3) 3350 (br), 1683, 1244 cm-1. Ion Spray MS 352 (M+H)+; 234 (M-(BOC+H20)+; 278 (M-73)+ (base peak); 410 (M+CH3COO-)-General procedure: A solution of 2, 6-difluorobenzaldehyde 7 (1.0g, 7.0mmol) and potassium carbonate (1.45g, 10.5mmol) in DMF (25mL) at 0C was added slowly with methyl thioglycolate (0.7mL, 7.7mmol) and the mixture was stirred at the same temperature for 30min. The reaction mixture was stirred at room temperature for 14h and then at 60C for 6h. Solvent was removed and the resulting residue was diluted with ethyl acetate (60mL) followed by washed with water (20mL). The organic layer was dried over Na2SO4, filtered, and concentrated to obtain a crude compound. The above crude compound (500mg, 2.38mmol) and potassium hydroxide (400mg, 7.14mmol) were taken into a mixture of EtOH/ water (12/2mL) and heated to reflux for 2h. The reaction mixture was cooled to room temperature and concentrated. The resulting residue was diluted with water (20mL), acidified with 6N HCl and extracted with ethyl acetate (60mL). The organic layer was dried over Na2SO4, filtered, and concentrated to afford colorless crystals. The resulting colorless crystals (1.0g, 5.1mmol) were mixed together with powdered copper (97mg, 1.53mmol) in quinoline (10mL) and heated at 185C for 2h. The reaction mixture was cooled to room temperature and diluted with ethyl acetate (60mL) and 2N HCl (20mL). The mixture was filtered and washed with ethyl acetate (50mL). The organic layer was dried over Na2SO4, filtered, and concentrated. The resulting crude product was purified by column chromatography using hexane to give colorless oil. To a solution of the above compound (1.0g, 6.57mmol) in dry THF (13mL) was added a 1.6M solution of n-BuLi in hexane (4.2mL, 6.57mmol) drop wise at-78C. The reaction mixture was stirred at same temperature for 30min and was added tri-n-butyltin chloride (1.79mL, 6.57mmol). The resulting solution was stirred for 1h at-78C and then at room temperature for another 1h. The reaction mixture was concentrated under reduced pressure and the resulting residue was diluted with ethyl acetate (60mL), washed with aqueous KF (2×20mL) and with water (2×20mL). The combined organic layers ware dried over MgSO4 and concentrated to obtain a crude product. A solution of the above crude compound (1.0g, 2.27mmol) and 2-bromopyridine (360mg, 2.27mmol) in toluene (22mL) was added with Pd(PPh3)4 (131mg, 0.114mmol). The reaction mixture was degassed thoroughly with nitrogen and stirred at 110C for 8h. After cooling to room temperature, the mixture was concentrated under reduced pressure. The obtained crude product was diluted with ethyl acetate, filtered through Celite, and washed with aqueous KF (2×15mL) followed by brine (15mL) and water (15mL). The organic layer was dried over MgSO4, filtered, and concentrated to afford a crude product which was purified by column chromatography using ethyl acetate/hexane (1:9) to afford the pure compound 8 as a white solid (260mg 40%).Scheme IA, step A: To a solution of 4- and 6-fluorobenzo[b]thiophene (1.70 g, 11.2 mmol) in dry THF (50 mL) at -78 C. was added 1.6 M n-BuLi in hexanes (9.08 mL, 14.5 mmol). The solution was stirred at -78 C. for 35 min. N-t-Butoxycarbonyl-4-piperidone (2.67 g, 15.6 mmol) dissolved in THF (10 mL) was added via a cannula at -78 C. The reaction mixture was kept at -78 C. for 1.5 h then allowed to warm to room temperature. The reaction was then quenched with 150 mL of saturated aqueous NH4Cl solution. The mixture was extracted (3×300 mL) with EtOAc. The combined organic layers were dried over MgSO4 and filtered. The filtrate was concentrated and purified by medium pressure chromatography (silica gel, 20% EtOAc/hexanes) to give the intermediate title compound as a white foam (2.24 g, 57%). mp 48-51 C. IR (CHCl3) 3350 (br), 1682, 1250 cm-1. Ion Spray MS 352 (M+H)+; 234 (M-(BOC+H2O)+; 278 (M-73)+ (base peak); 410 (M+CH3COO-)-.

Molecular Weight:152.19
XLogP3:3
Hydrogen Bond Acceptor Count:2
Exact Mass:152.00959950
Monoisotopic Mass:152.00959950
Topological Polar Surface Area:28.2
Heavy Atom Count:10
Complexity:126
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes