Iodine → Tert-butyl(2,6-dimethoxyphenyl)(iodomethyl)phosphine

Temperature

-78 °C

To a solution of 1 (7.4 g, 28.9 mmol, 1 equiv.) and TMEDA (6.50 mL, 43 mmol, 1.5 equiv.) in THF (40 mL) at −78° C. was added 2.5 M BuLi in hexanes (13.9 mL, 35 mmol, 1.2 equiv.) over 10 min. The resulting mixture was stirred at −78° C. for 1 h. To the mixture at −78° C. was added iodine (11.0 g, 43 mmol, 1.5 equiv.) in THF (20 mL) while controlling the temperature <−70° C. After the addition, the mixture was further stirred at −78° C. for 0.5 h and then warmed to 25° C. over 1 h. To the mixture was added 10% NaHSO3 solution (100 mL) and dichloromethane (100 mL). The dichloromethane layer was washed with brine (100 mL), dried over sodium sulfate, concentrated, and purified by silica gel column chromatography (eluents: EtOAc to EtOAc/MeOH 10/1; monitored at 290 nm) to provide 2 as a thick oil (8.8 g, 23.0 mmol, 80%). 1HNMR (400 MHz, CDCl3): δ=7.40 (t, J=8.4 Hz, 1H), 6.56 (dd, J=8.4, 4.0 Hz, 2H), 3.80 (s, 6H), 3.79 (m, 1H), 3.34 (dd, J=11.2, 8.3 Hz, 1H), 1.18 (d, J=15.6 Hz, 9H); 31PNMR (162 MHz, CDCl3): δ=50.4; 13CNMR (100 MHz, CDCl3): δ=163.2, 134.2, 104.9 (d, J=63 Hz), 104.3 (d, J=6 Hz), 55.9, 35.3 (d, J=71 Hz), 25.0, −1.8 (d, J=59 Hz); ESI-MS: m/z 383 [M+H]+.

1. customthe temperature <−70° C
2. additionAfter the addition
3. stirringthe mixture was further stirred at −78° C. for 0.5 h
4. temperaturewarmed to 25° C. over 1 h
5. washThe dichloromethane layer was washed with brine (100 mL)
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated
8. custompurified by silica gel column chromatography (eluents: EtOAc to EtOAc/MeOH 10/1; monitored at 290 nm)

ORD record

ord-a842b3de93154ce5bb63eadf24f6f1f3

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08552212B2