1-(5-BROMO-PYRIDIN-2-YL)-ETHANONE

2, 5-dibromo-pyridine (I-1-1) 8g the (33.7mmol) and toluene 337mL was stirred at -40 under a nitrogen atmosphere. After stirring for 40 minutes was added n- butyl lithium 1.6M in hexane 21.4mL a (1.02eq) in which, in addition N, N-dimethylacetamide (DMAc) 9.38mL (3.0eq), stirred It was slowly heated to 20 while. Thereafter, saturated aqueous ammonium chloride solution was added to quench the reaction, and extraction and liquid separation. The extract was purified by silica gel column chromatography, 2-acetyl-5-bromopyridine to give (compound the I-1-2) of a white solid 6.74 g (100percent yield).To a solution of 2, 5-dibromopyridine (5 g, 22.026 mmol) in anhydrous toluene (200 mL) at -50 °C was added n-butyllithium (13.75 mL, 22.026 mmol) (1.6M in hexane) dropwise. The resulted mixture was stirred at -50 °C temperature for 45 mi N, Ndimethylacetamide (3.61 mL, 37.44 mmol) was added dropwise at the same temperatureand then allowed to reach room temperature slowly. The reaction mixture was stirred at room temperature for 1 h and quenched with saturated ammonium chloride solution, then extracted with EtOAc. The organic layer was dried over sodium sulfate, concentrated and purified by column chromatography (60-120 silica gel, 1percent EtOAc/hexane) to provide the product of Step 1 (2.9 g, 65percent yield) as a white solid. LCMS retention time: 1.46 mm(Method 7).Intermediate 10: 1-(5-Bromopyridin-2-yl)ethanone; see W098/46605; 5-Bromo-2-cyanopyridine (Markevitch, David Y.; Rapta, Miroslav; Hecker, Scott J. ; Renau, Thomas E. ; Synth. Commun.; 33; 19; 2003; 3285 - 3290) (8 g, 43.7 mmol) was dissolved in dry THF (200 mL) and cooled to - 20°C. Methylmagnesium bromide (43.7 mL, 3M) was added drop wise and the temperature was held between -20°C and -10°C for 3 hours. The reaction mixture was cooled to -40°C and conc. HCI (4.5 mL) in water (15 mL) was added dropwise. It was stirred for 10 minutes at -35°C and then poured into a beaker with potassium phosphate buffer (300 mL, 1M, pH 7), under stirring. Ethyl acetate (300 mL) was added and the organic phase was dried over sodium sulfate. Upon concentration at room temperature under reduced pressure to - 50 mL the product crystallized, 2.4 g, mp 112°C. The mother liquor was further concentrated and chromatographed on silica gel with dichloromethane/ ethylacetate (100:1) to give another 3.25 g product (65percent combined yield). Intermediate 10: 1-(5-Bromopyridin-2-yl)ethanone; See W098/46605; 5-Bromo-2-cyanopyridine (Markevitch, David Y. ; Rapta, Miroslav; Hecker, Scott J. ; Renau, Thomas E. ; Synth. Commun.; 33; 19; 2003; 3285 - 3290) (8 g, 43.7 mmol) was dissolved in dry THF (200 mL) and cooled to - 20°C. Methylmagnesium bromide (43.7 mL, 3M) was added drop wise and the temperature was held between -20°C and -10°C for 3 hours. The reaction mixture was cooled to -40°C and concentrated HCl (4.5 mL) in water (15 mL) was added dropwise. It was stirred for 10 minutes at -35°C and then poured into a beaker with potassium phosphate buffer (300 mL, 1M, pH 7), under stirring. Ethyl acetate (300 mL) was added and the organic phase was dried over sodium sulfate. Upon concentration at room temperature under reduced pressure to - 50 mL the product crystallized, 2.4 g, mp 112°C. The mother liquor was further concentrated and chromatographed on silica gel with dichloromethane/ ethylacetate (100:1) to give another 3.25 g product (65percent combined yield). (at)H-NMR (DMSO-d(at)) No.: 2.60 (s, 3H) ; 7.88 (dd, 1H) ; 8.25 (dd, 1H) ; 8.86 (d, 1H).5-Bromopicolinonitrile (5.4 g, 29.7 mmol) was dissolved in anhydrous THF (120 mL) and cooled to -20Step 2. Intermediate 10: 1-(5-Bromopyridin-2-yl)ethanone; see W098/46605; 5-Bromo-2-cyanopyridine (Markevitch, David Y.; Rapta, Miroslav; Hecker, Scott J. ; Renau, Thomas E. ; Synth. Commun.; 33; 19; 2003; 3285 - 3290) (8 g, 43.7 mmol) was dissolved in dry THF (200 mL) and cooled to - 20C. Methylmagnesium bromide (43.7 mL, 3M) was added drop wise and the temperature was held between -20C and -10C for 3 hours. The reaction mixture was cooled to -40C and conc. HCI (4.5 mL) in water (15 mL) was added dropwise. It was stirred for 10 minutes at -35C and then poured into a beaker with potassium phosphate buffer (300 mL, 1M, pH 7), under stirring. Ethyl acetate (300 mL) was added and the organic phase was dried over sodium sulfate. Upon concentration at room temperature under reduced pressure to - 50 mL the product crystallized, 2.4 g, mp 112C. The mother liquor was further concentrated and chromatographed on silica gel with dichloromethane/ ethylacetate (100:1) to give another 3.25 g product (65% combined yield). ¹H-NMR (DMSO-d6) No.: 2.60 (s, 3H) ; 7.88 (dd, 1H); 8.25 (dd, 1H); 8.86 (d, 1H).Intermediate 10: 1-(5-Bromopyridin-2-yl)ethanone; See W098/46605; 5-Bromo-2-cyanopyridine (Markevitch, David Y. ; Rapta, Miroslav; Hecker, Scott J. ; Renau, Thomas E. ; Synth. Commun.; 33; 19; 2003; 3285 - 3290) (8 g, 43.7 mmol) was dissolved in dry THF (200 mL) and cooled to - 20C. Methylmagnesium bromide (43.7 mL, 3M) was added drop wise and the temperature was held between -20C and -10C for 3 hours. The reaction mixture was cooled to -40C and concentrated HCl (4.5 mL) in water (15 mL) was added dropwise. It was stirred for 10 minutes at -35C and then poured into a beaker with potassium phosphate buffer (300 mL, 1M, pH 7), under stirring. Ethyl acetate (300 mL) was added and the organic phase was dried over sodium sulfate. Upon concentration at room temperature under reduced pressure to - 50 mL the product crystallized, 2.4 g, mp 112C. The mother liquor was further concentrated and chromatographed on silica gel with dichloromethane/ ethylacetate (100:1) to give another 3.25 g product (65% combined yield). (at)H-NMR (DMSO-d(at)) No.: 2.60 (s, 3H) ; 7.88 (dd, 1H) ; 8.25 (dd, 1H) ; 8.86 (d, 1H).5-Bromopicolinonitrile (5.4 g, 29.7 mmol) was dissolved in anhydrous THF (120 mL) and cooled to -200C. MeMgBr (35 mL, IM in Et2O) was added dropwise, and the reaction mixture was stirred at -200C for 3 h. The reaction mixture was cooled to -40 0C, and neutralized with cone. HCl. The solvent was removed under reduced pressure. The residue was dissolved in EtOAc and washed with water. The aqueous layer was extracted with EtOAc. The combined organic phase was dried (Na2SO4) and evaporated under vacuum. The crude product was purified by column chromatography on silica gel (EtOAc - hexanes) to give l-(5-bromopyridin-2-yl)ethanone (1.9 g, 30% yield).The reaction is carried out unter nitrogen atmosphere. To a solution of lodo benzene diacetate (40.250 g; 0.125 mol) in 500 ml_ acetonitrile, trifluoromethanesulfonic acid (37.500 g; 0.250 mol) is added. The mixture is stirred for 1 hour. Then 1-(5-Bromopyridin-2-yl)ethan-1 -one (25.000 g; 0.125 mol) is added. The mixture is stirred for 4 hours under reflux. The mixture is cooled to room temperature and poured into saturated aqueous sodium bicarbonate solution and extracted with dichloromethane. The organic layer is washed with brine, dried over magnesium sulfate, filtered and concentrated. The mixture is purified by reverse phase chromatography-HPLC.Yield: 2.0 g (7 % of theory)Mass spectrometry (ESI+): m/z = 239/241 [M+H]+In a 200 mL round bottom flask, l-(5-bromopyridin-2-yl)ethan-l-one (20 g, 0.10 mol) and RuCl(p-cymene)[(S, S)-Ts-DPEN] (0.64 g, 1.0 mmol) (Aldrich, 703915) were dissolved in CH2CI2 (0.10 L). A premixed solution of formic acid (17 mL, 0.43 mol) in triethylamine (35 mL, 0.25 mol) was added to the reaction mixture. After stirring at rt overnight, the resulting mixture was diluted with CH2CI2 and poured into aq. sat. Na2HC03 (400 mL). The organic layer was separated, and the aqueous layer extracted with CH2CI2. The combined organic layers were dried over MgSC , filtered, and concentrated. Purification via silica gel chromatography afforded the product as a yellow oil (20 g, 97% yield, 80% ee). Further purification via chiral preparatory HPLC on a Phenomenx Lux Amylose-1 column (3% EtOH/hexanes, 20 mL/min) afforded the title compound as a single isomer, the first eluting enantiomer (tR = 3 min). NMR (400 MHz, CDC13) delta 8.60 (d, J = 2.2 Hz, 1H), 7.81 (dd, J = 8.4, 2.3 Hz, 1H), 7.22 (d, J = 8.4 Hz, 1H), 5.04 - 4.61 (m, 1H), 3.73 (d, J = 5.0 Hz, 1H), 1.49 (d, J= 6.6 Hz, 3H).

Molecular Weight:200.03
XLogP3:1.6
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:198.96328
Monoisotopic Mass:198.96328
Topological Polar Surface Area:30
Heavy Atom Count:10
Complexity:138
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes