Hydrochloric Acid → HCID 49869889, compound

To an ice-salt cooled suspension of 5-(benzyloxy)-1-methyl-2-(2,2,2-trifluoro-1-hydroxyethyl)pyridin-4(1H)-one (1.20 g, 3.8 mmol) and a 10% sodium bicarbonate solution (4 mL) in acetone (36 mL) were placed in a 250-mL 1-N RB equipped with a magnetic stir bar to give a suspension was added a solution of potassium bromate (99 mg, 0.6 mmol) dissolved in de-ionized water (3 mL). A solution of TEMPO (31 mg, 0.2 mmol) in acetone (1 mL) was added to the suspension, followed by a solution of sodium hypochlorite (0.96 M, 6.5 mL, 6.24 mmol). HPLC was used to monitor the progress of the reaction (HPLC Column: XTerra MS C18, 4.6×250 mm; A=Aqueous phase: 4 mM Tris, 2 mM EDTA, pH 7.4; B=Organic phase: CH3CN; Flow rate=1.0 mL/min; Injection volume=5 μL; Wavelength (λ): 220, 254, 280, 450 nm. Isocratic method; aqueous:organic=75:25, RT of the SM=10.30 min, RT of the product=11.37 min, the conversion was >99%). The reaction mixture was filtered. The filtrate was collected and concentrated to give a semi-solid. The semi-solid was suspended in dichloromethane (40 mL) and brine (30 mL). The mixture was stirred and the solid was collected by suction filtration. The solid was washed with de-ionized water (15 mL×4) and with ether (15 mL×4). Thus, 5-(benzyloxy)-1-methyl-2-(2,2,2-trifluoro-1,1-dihydroxyethyl)pyridin-4(1H)-one was obtained (0.93 g). Yield=73%; HPLC Method 2, purity (AUC)=99.4% at 280 nm; 1H NMR (DMSO-D6) δ (ppm): 8.45 (s, 2H), 7.67 (s, 1H), 7.4 (m, 5H), 6.66 (s, 1H), 5.04 (s, 2H), 3.85 (s, 3H); MS-ESI m/z 330 [M+1]+, 91 (100%). (b) Debenzylation of 5-(benzyloxy)-1-methyl-2-(2,2,2-trifluoro-1,1-dihydroxyethyl)pyridin-4(1H)-one (700 mg, 2.1 mmol) was carried out in a hydrochloric acid solution (4M, 22 mL) by heating to reflux. HPLC was used to monitor the progress of the reaction (HPLC Method 2, RT of the SM=11.47 min, RT of the product=3.26 min, conversion>98%). The resulting solution was concentrated to give oil. About half of the oily residue was weighed out, and dissolved in de-ionized water. The pH of the resulting solution was adjusted to 6 with a 6.00 N sodium hydroxide solution (160 μL). Solid appeared upon stirring. The solid was collected by filtration, thoroughly washed with de-ionized water and ether. Thus, a sample of 5-hydroxy-1-methyl-2-(2,2,2-trifluoro-1,1-dihydroxyethyl)pyridin-4(1H)-one (Apo7072) was obtained (118 mg). Yield=46%; HPLC Method: Column: XTerra MS C18, 4.6×250 mm; A=Aqueous phase: 4 mM Tris, 2 mM EDTA, pH 7.4; B=Organic phase: CH3CN; Flow rate=1.0 mL/min; Injection volume=5 μL; Wavelength (λ): 220, 254, 280, 450 nm. Isocratic method; aqueous:organic=75:25, purity (AUC)=99.5% at 280 nm; 1H NMR (DMSO-D6+a few drops of D2O) δ (ppm): 7.47 (s, 1H), 6.66 (s, 1H), 3.82 (s, 3H); MS-ESI m/z 240 [M+1]+, 222 (100%), 125.

1. temperatureby heating to reflux
2. customthe progress of the reaction (HPLC Method 2, RT of the SM=11.47 min, RT of the product=3.26 min, conversion>98%)
3. concentrationThe resulting solution was concentrated
4. customto give oil
5. filtrationThe solid was collected by filtration
6. washthoroughly washed with de-ionized water and ether

ORD record

ord-e9d6e9a5520144bf87f758c2b7cbbfaa

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09073865B2