4-bromo-2-fluoro-5-methylphenol

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-3-hydroxydihydrofuran-2(3H)-one (2.0 g, 20 mmol) was suspended in Toluene (150 mL) and triphenylphosphine (6.2 g, 24 mmol) and 4-bromo-2-fluoro-5-methylphenol (4.8 g, 24 mmol) were added and cooled to 0° C. The solution was degassed with nitrogen bubble for 10 minutes. Di-tert-butyl diazene-1,2-dicarboxylate (5.4 g, 24 mmol) was dissolved in toluene (40 mL) and added to the reaction over 5 minutes. The reaction was allowed to slowly warm to ambient temperature overnight. The toluene was removed and the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes) to afford (S)-3-(4-bromo-2-fluoro-5-methylphenoxy)dihydrofuran-2(3H)-one (2.9 g, 10 mmol, 51% yield). The solution was degassed with nitrogen bubble for 10 minutes added to the reaction over 5 minutes to slowly warm to ambient temperature overnight The toluene was removed the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Fluoro-5-methylphenol (5.0 g, 40 mmol) was dissolved in chloroform (200 mL). Tetrabutylammonium tribromide (19 g, 40 mmol) was added and the reaction stirred at ambient temperature for 30 minutes. The reaction was concentrated and purified over silica gel (20% EtOAc in hexanes) to afford 4-bromo-2-fluoro-5-methylphenol (7.8 g, 38 mmol, 96% yield) as an amber oil. The reaction was concentrated purified over silica gel (20% EtOAc in hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-fluoro-5-methylphenol (40 g, 0.19 mol), cesium carbonate (75 g, 0.23 mol), and iodomethane (15 ml, 0.23 mol) were combined in 100 ml of DMF and stirred at RT for one hour (exothermic). The solution was diluted with ethyl acetate and filtered. The solution was washed with water twice, dried with anhydrous sodium sulfate, filtered, and concentrated. The product was purified via silica gel column chromatography (RediSep 330 g column) using 0-50% ethyl acetate in hexane to afford 1-bromo-5-fluoro-4-methoxy-2-methylbenzene (38 g, 89% yield) as a colorless liquid. No [M+H] peak by LCMS. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.24 (s, 3 H) 3.76 (s, 3 H) 6.73 (d, J=8.80 Hz, 1 H) 7.13 (d, J=10.56 Hz, 1 H) filtered The solution was washed with water twice dried with anhydrous sodium sulfate filtered concentrated The product was purified via silica gel column chromatography (RediSep 330 g column)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-fluoro-5-methylphenol (23.8 g, 0.19 mol) and bromine (9.7 ml, 0.19 mol) are combined in 50 ml of glacial acetic acid and stirred at RT for one hour. Acetic acid was removed under vacuum. The liquid was diluted with ethyl acetate and washed with water. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated to afford 4-bromo-2-fluoro-5-methylphenol (38 g, 98% yield) as a colorless liquid. No [M+H] peak by LCMS. 1H NMR (400 MHz, CHLOROFORM-d) ppm 1.98 (s, 1 H) 2.22 (s, 3 H) 6.81 (dd, J=9.15, 0.54 Hz, 1 H) 7.17 (d, J=9.88 Hz, 1 H) Acetic acid was removed under vacuum The liquid was diluted with ethyl acetate washed with water The organic layer was washed with brine dried over anhydrous sodium sulfate filtered concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-fluoro-5-methylphenol (40 g, 0.19 mol), cesium carbonate (75 g, 0.23 mol), and iodomethane (15 ml, 0.23 mol) were combined in 100 ml of DMF and stirred at RT for one hour (exothermic). The solution was diluted with ethyl acetate and filtered. The solution was washed with water twice, dried with anhydrous sodium sulfate, filtered, and concentrated. The product was purified via silica gel column chromatography (RediSep 330 g column) using 0-50% ethyl acetate in hexane to afford 1-bromo-5-fluoro-4-methoxy-2-methylbenzene (38 g, 89% yield) as a colorless liquid. No [M+H] peak by LCMS. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.24 (s, 3 H) 3.76 (s, 3 H) 6.73 (d, J=8.80 Hz, 1 H) 7.13 (d, J=10.56 Hz, 1 H) filtered The solution was washed with water twice dried with anhydrous sodium sulfate filtered concentrated The product was purified via silica gel column chromatography (RediSep 330 g column)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-fluoro-5-methylphenol (23.8 g, 0.19 mol) and bromine (9.7 ml, 0.19 mol) are combined in 50 ml of glacial acetic acid and stirred at RT for one hour. Acetic acid was removed under vacuum. The liquid was diluted with ethyl acetate and washed with water. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated to afford 4-bromo-2-fluoro-5-methylphenol (38 g, 98% yield) as a colorless liquid. No [M+H] peak by LCMS. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.98 (s, 1 H) 2.22 (s, 3 H) 6.81 (dd, J=9.15, 0.54 Hz, 1 H) 7.17 (d, J=9.88 Hz, 1 H) Acetic acid was removed under vacuum The liquid was diluted with ethyl acetate washed with water The organic layer was washed with brine dried over anhydrous sodium sulfate filtered concentrated

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-3-hydroxydihydrofuran-2(3H)-one (2.0 g, 20 mmol) was suspended in Toluene (150 mL) and triphenylphosphine (6.2 g, 24 mmol) and 4-bromo-2-fluoro-5-methylphenol (4.8 g, 24 mmol) were added and cooled to 0° C. The solution was degassed with nitrogen bubble for 10 minutes. Di-tert-butyl diazene-1,2-dicarboxylate (5.4 g, 24 mmol) was dissolved in toluene (40 mL) and added to the reaction over 5 minutes. The reaction was allowed to slowly warm to ambient temperature overnight. The toluene was removed and the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes) to afford (S)-3-(4-bromo-2-fluoro-5-methylphenoxy)dihydrofuran-2(3H)-one (2.9 g, 10 mmol, 51% yield). The solution was degassed with nitrogen bubble for 10 minutes added to the reaction over 5 minutes to slowly warm to ambient temperature overnight The toluene was removed the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Fluoro-5-methylphenol (5.0 g, 40 mmol) was dissolved in chloroform (200 mL). Tetrabutylammonium tribromide (19 g, 40 mmol) was added and the reaction stirred at ambient temperature for 30 minutes. The reaction was concentrated and purified over silica gel (20% EtOAc in hexanes) to afford 4-bromo-2-fluoro-5-methylphenol (7.8 g, 38 mmol, 96% yield) as an amber oil. The reaction was concentrated purified over silica gel (20% EtOAc in hexanes)

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (R)-3-hydroxydihydrofuran-2(3H)-one (2.0 g, 20 mmol) was suspended in Toluene (150 mL) and triphenylphosphine (6.2 g, 24 mmol) and 4-bromo-2-fluoro-5-methylphenol (4.8 g, 24 mmol) were added and cooled to 0° C. The solution was degassed with nitrogen bubble for 10 minutes. Di-tert-butyl diazene-1,2-dicarboxylate (5.4 g, 24 mmol) was dissolved in toluene (40 mL) and added to the reaction over 5 minutes. The reaction was allowed to slowly warm to ambient temperature overnight. The toluene was removed and the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes) to afford (S)-3-(4-bromo-2-fluoro-5-methylphenoxy)dihydrofuran-2(3H)-one (2.9 g, 10 mmol, 51% yield). The solution was degassed with nitrogen bubble for 10 minutes added to the reaction over 5 minutes to slowly warm to ambient temperature overnight The toluene was removed the oily residue was purified over silica gel (20 to 40% EtOAc in hexanes)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Bromo-2-fluoro-5-methylphenol (40 g, 0.19 mol), cesium carbonate (75 g, 0.23 mol), and iodomethane (15 ml, 0.23 mol) were combined in 100 ml of DMF and stirred at RT for one hour (exothermic). The solution was diluted with ethyl acetate and filtered. The solution was washed with water twice, dried with anhydrous sodium sulfate, filtered, and concentrated. The product was purified via silica gel column chromatography (RediSep 330 g column) using 0-50% ethyl acetate in hexane to afford 1-bromo-5-fluoro-4-methoxy-2-methylbenzene (38 g, 89% yield) as a colorless liquid. No [M+H] peak by LCMS. 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 2.24 (s, 3 H) 3.76 (s, 3 H) 6.73 (d, J=8.80 Hz, 1 H) 7.13 (d, J=10.56 Hz, 1 H) filtered The solution was washed with water twice dried with anhydrous sodium sulfate filtered concentrated The product was purified via silica gel column chromatography (RediSep 330 g column)