2-Chloro-3-nitrobenzoic acid → (2-Chloro-3-nitrophenyl)methanol

Temperature

-70 °C

3-Nitro-2-chlorobenzoic acid (25.51 g, 126.56 mmol) was dissolved in anhydrous THF (400 mL) under a nitrogen atmosphere. The solution was cooled to −70° C. (internal temperature) under N2 flush. DIBAL-H (260 mL, 1.0M in hexanes) was added dropwise over about 1½ h (internal temperature was maintained below −65° C.). The reaction was allowed to slowly warm to room temperature and was stirred 12 h. The reaction was cooled to −70° C. and 50 mL of MeOH was added dropwise. The reaction mixture was placed in an H2O/ice bath and a 1M Rochelle's salt solution was slowly added in. This solution was stirred for 1 h at room temperature, then filtered through diatomaceous earth. The THF was concentrated in vacuo and the remaining aqueous solution was extracted 3 times with EtOAc. The combined organic layers were washed with brine, dried with MgSO4, filtered, and evaporated to obtain 14.4 g (61%) of the desired 3-nitro-2-chlorobenzyl alcohol as a yellow solid.

1. customflush
2. additionDIBAL-H (260 mL, 1.0M in hexanes) was added dropwise over about 1½ h
3. temperature(internal temperature was maintained below −65° C.)
4. temperatureto slowly warm to room temperature
5. temperatureThe reaction was cooled to −70° C.
6. addition50 mL of MeOH was added dropwise
7. customThe reaction mixture was placed in an H2O/ice bath
8. additiona 1M Rochelle's salt solution was slowly added in
9. stirringThis solution was stirred for 1 h at room temperature
10. filtrationfiltered through diatomaceous earth
11. concentrationThe THF was concentrated in vacuo
12. extractionthe remaining aqueous solution was extracted 3 times with EtOAc
13. washThe combined organic layers were washed with brine
14. dry with materialdried with MgSO4
15. filtrationfiltered
16. customevaporated

ORD record

ord-aa7ab3580e5d49f68b503ab7856bce60

Source dataset

uspto-grants-2009_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07550461B2