Hydrochloric Acid → 5-Chloro-2-fluoro-4-hydroxybenzaldehyde

To 4-bromo-2-chloro-5-fluoro-phenol (104, 2.25 g, 9.98 mmol) in tetrahydrofuran (50 mL), cooled to −78° C. under an atmosphere of nitrogen, was added n-butyllithium (2.50 M in hexane, 4.21 mL) and 1,2-bis-(chloro-dimethyl-silanyl)-ethane (1.08 g, 5.01 mmol). The reaction was stirred at room temperature for 2 hours. The reaction was cooled to −78° C., followed by adding tert-butyllithium (1.70 M in hexane, 12.4 mL). After 30 minutes, N,N-dimethylformamide (0.97 mL, 0.0125 mol) was added to the reaction. After 30 minutes, the reaction was warmed to room temperature for 10 minutes. 5N HCl (20 mL) was added to the reaction. After 30 minutes, the reaction was poured into water and extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated and purified by silica gel column chromatography eluting with 20% to 100% ethyl acetate in hexane to give the desired compound (105, 0.50 g, 28.7). 1H NMR consistent with structure.

1. temperatureThe reaction was cooled to −78° C.
2. waitAfter 30 minutes
3. waitAfter 30 minutes
4. temperaturethe reaction was warmed to room temperature for 10 minutes
5. waitAfter 30 minutes
6. extractionextracted with ethyl acetate
7. dry with materialThe organic layer was dried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationThe filtrate was concentrated
10. custompurified by silica gel column chromatography
11. washeluting with 20% to 100% ethyl acetate in hexane

ORD record

ord-090110f0cf48464eba8ede3262c10551

Source dataset

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07872018B2