Pyridine → (4R)-(+)-(4-pyridyl)-2-(4-nitrophenoxy)-2-oxo-1,3,2-dioxaphosphorinane

온도

0 °C

To a stirred solution of 4-nitrophenyl phosphorodichloridate (9.2 g, 36 mmol) in THF (100 mL) at 0° C. was slowly added pyridine (7.9 mL, 98 mmol) over 30 minutes. The reaction mixture was stirred for 5 minutes at 0° C. and slowly added to a solution of R-(+)-1-(4-pyridyl)-1,3-propane diol 95.8% ee, 5 g, 32.7 mmol) and triethylamine (15.6 mL, 114 mmol) in THF (300 mL) at 0° C. over 1.5 hours. The reaction mixture was allowed to warm to room temperature and stirred for 2.5 hours. Sodium 4-nitrophenoxide (18.17 g, 131 mmol) was added and the heterogeneous orange reaction mixture was heated at 40° C. for 4.5 hours. The reaction mixture was cooled to 0° C., quenched with a saturated aqueous solution of, ammonium chloride (250 mL) and the layers were separated. The organics were washed with a saturated aqueous solution of ammonium chloride (200 mL) and the combined aqueous washes were back-extracted with dichloromethane (100 mL). The combined organic extracts were washed with a 0.3 N aqueous solution of sodium hydroxide (200 mL×4) and dried over magnesium sulfate. The filtered solution was concentrated under reduced pressure to give an oil that crystallized upon standing. The yellow solid was recrystallized from 100 mL of 2-propanol to afford the desired trans-phosphate (12) as a white solid (95% ee, [α]D20+74.2 (c 1.0, MeOH)).

1. customat 0° C.
2. customover 30 minutes
3. temperatureto warm to room temperature
4. stirringstirred for 2.5 hours
5. temperaturethe heterogeneous orange reaction mixture was heated at 40° C. for 4.5 hours
6. temperatureThe reaction mixture was cooled to 0° C.
7. customquenched with a saturated aqueous solution of, ammonium chloride (250 mL)
8. customthe layers were separated
9. washThe organics were washed with a saturated aqueous solution of ammonium chloride (200 mL)
10. extractionthe combined aqueous washes were back-extracted with dichloromethane (100 mL)
11. washThe combined organic extracts were washed with a 0.3 N aqueous solution of sodium hydroxide (200 mL×4)
12. dry with materialdried over magnesium sulfate
13. concentrationThe filtered solution was concentrated under reduced pressure
14. customto give an oil that
15. customcrystallized
16. customThe yellow solid was recrystallized from 100 mL of 2-propanol

ORD 기록

ord-b731b6acee0840beb0e8adef243b6ce1

출처 데이터셋

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US07553826B2