Carbon Dioxide → 3-Chloro-5-(tert-butyldimethylsilyloxy)benzoic acid

To “Rieke Mg” (0.21 mol; Rieke, R. D.; Bales, S. E.; Hudnall, P. M.; Burns, T. P.; Poindexter, G. S. Org. Synth. Collective Volume VI, 1988, 845.) in tetrahydrofuran (1000 mL) was added ether 13 (27.7 g, 0.10 mol). After the reaction mixture was stirred for 20 min at ambient temperature there was an exotherm observed. The exotherm subsided within 5 min, and the reaction mixture was cooled to 20° C. with an ice bath. After 15 min, the reaction mixture was cooled to −78° C. To the cool reaction mixture was added CO2 gas for 30 min. The reaction mixture was warmed to ambient temperature, then diluted with cold (0° C.) 10% aqueous HCl (150 mL) and ethyl acetate (400 mL). The aqueous phase was extracted with ethyl acetate (400 mL). The combined organic phases were washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo. The resulting solid was recrystallized from acetonitrile to provide 14 as fluffy white needles (19.3 g, 64%). 1H NMR (300 MHz, CDCl3) δ 7.70 (s, 1H), 7.43 (s, 1H), 7.08 (s, 1H), 0.99 (s, 9H), 0.23 (s, 6H). IR (KBr) 2957, 1697, 1578, 1434, 1297, 1266, 1115, 990, 871 cm−1.

1. waitThe exotherm subsided within 5 min
2. temperaturethe reaction mixture was cooled to 20° C. with an ice bath
3. waitAfter 15 min
4. temperaturethe reaction mixture was cooled to −78° C
5. customTo the cool reaction mixture
6. temperatureThe reaction mixture was warmed to ambient temperature
7. extractionThe aqueous phase was extracted with ethyl acetate (400 mL)
8. washThe combined organic phases were washed with brine
9. dry with materialdried over anhydrous MgSO4
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customThe resulting solid was recrystallized from acetonitrile

ORD-Eintrag

ord-c08ce82b9cda41a599d84559fee9083f

Quelldatensatz

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06344486B1