Sulfuric Acid → 3-Bromo-4-methylphenol

Temperatur

0 °C

To a 0° C. mixture of 3-bromo-4-methyl aniline (5 g; 27 mmol) and H2SO4 (5.5 mL of a 16 M solution) in H2O (7.5 mL) was added dropwise a solution of aqueous NaNO2 (1.93 g; 28 mmol in 7.5 mL H2O). The reaction was stirred at 0° C. for 30 min, then was heated at 50° C. for 2 h, then was cooled to RT and extracted with EtOAc (2×). The combined organic extracts were washed with H2O, dried (Na2SO4) and concentrated in vacuo to give 3-bromo-4-methyl phenol (1.72 g; 34%) as an oil. This phenol was converted to 3-bromo-4-methyl phenyl chloroformate (1.9 g; 82%) using the same procedure (phosgene/dimethylaniline/heat) as for 3-fluoro-4-methyl phenyl chloroformate above.

1. temperaturewas heated at 50° C. for 2 h
2. temperaturewas cooled to RT
3. extractionextracted with EtOAc (2×)
4. washThe combined organic extracts were washed with H2O
5. dry with materialdried (Na2SO4)
6. concentrationconcentrated in vacuo

ORD-Eintrag

ord-03e350e0a3fc454085162cb70907dbec

Quelldatensatz

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07084162B2