Pyridine → HCID 6951703, compound

Temperature

0 °C

In a 25 ml nitrogen-purged flask, with exclusion of air and moisture, 8.28 mmol (1.01 g, 1.00 ml) of (S)-1-phenylethanol (Fluka, 99% ee), 12.4 mmol (1.50 equ., 983 mg, 1.00 ml) of pyridine and 15 ml of dichloromethane are charged and cooled down to 0° C. (ice bath). With stirring, 10.8 mmol (1.30 equ., 1.10 g, 1.02 ml) of acetic anhydride is added dropwise over 10 min. Within a period of 12 h, the mixture is warmed up to room temperature and successively extracted twice each with 20 ml of 1 M aqueous hydrochloric acid solution, saturated sodium hydrogencarbonate solution and saturated sodium chloride solution. The organic phase is dried over magnesium sulfate, separated from the desiccant by filtration and freed from solvent in a rotary evaporator. The crude product was purified by chromatography over silica gel (mobile solvent: hexane:ethyl acetate=9:1). The product fractions are combined and freed from solvent in a rotary evaporator. After drying in an oil-pump vacuum, a clear liquid remains (1.25 g, 7.62 mmol, 92%). Analytics: 1H-NMR (CDCl3, 200 MHz): δ=1.52 (d) 3J=6.6 Hz [3H], 2.06 (s) [3H], 5.94 (q) 3J=6.6 Hz [1H], 7.24-7.38 (m) [5H]; 13C-{1H}-NMR (CDCl3, 50 MHz): δ=21.4 (s), 22.2 (s), 72.3 (s), 126.1 (s), 127.9 (s), 128.5 (s), 141.7 (s), 170.3 (s); MS (EI, 70 eV, pos. ions): m/z (% rel. int.): 164 (25) [M+], 122 (77), 107 (36), 105 (69), 104 (100), 103 (24), 79 (27), 78 (27), 77 (43), 51 (24), 43 (90); EA: C: 72.95% (calc. 73.15%), H: 7.28% (calc. 7.37%); GC (Hewlett Packard 5890, 25 m fused silica, 0.25 inner diameter, 2,6-dimethyl-3-pentyl-β-CD (95% methyl-/5% phenylpolysiloxane), FID, 80° C., 4° C. min−1, 120° C. 0.2 min iso, 0.63 bar hydrogen): 99.8% ee.

1. customIn a 25 ml nitrogen-purged flask
2. temperaturethe mixture is warmed up to room temperature
3. extractionsuccessively extracted twice each with 20 ml of 1 M aqueous hydrochloric acid solution, saturated sodium hydrogencarbonate solution and saturated sodium chloride solution
4. dry with materialThe organic phase is dried over magnesium sulfate
5. customseparated from the
6. filtrationdesiccant by filtration
7. customfreed from solvent in a rotary evaporator
8. customThe crude product was purified by chromatography over silica gel (mobile solvent: hexane:ethyl acetate=9:1)
9. customfreed from solvent in a rotary evaporator
10. customAfter drying in an oil-pump vacuum
11. customGC (Hewlett Packard 5890, 25 m fused silica, 0.25 inner diameter, 2,6-dimethyl-3-pentyl-β-CD (95% methyl-/5% phenylpolysiloxane), FID, 80° C., 4° C. min−1, 120° C. 0.2 min iso, 0.63 bar hydrogen)

ORD record

ord-ed9979439b8c45619bdf407908988b4b

Source dataset

uspto-grants-2004_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06824982B1