Sulfuric Acid → 3-Chloro-o-cresol

Temperatur

90 °C

A solution of concentrated sulphuric acid (7.3 mL) in water (97 mL) was added to 3-chloro-2-methylaniline (0.84 mL, 7.06 mmol) and the mixture heated at 90° C. until solution was achieved. The reaction mixture was cooled to 0° C. and a solution of sodium nitrite (510 mg, 12.75 mmol) in water (5 mL) was added dropwise. The reaction mixture was allowed to warm to ambient temperature over 2 h. Excess sodium nitrite was destroyed by the addition of urea. The resultant mixture was added to a solution of concentrated sulphuric acid (5.0 mL) in water (55 mL), heated to 90° C. and stirred at this temperature for a further 1 h. The resultant product mixture was filtered through dicalite and extracted with dichloromethane (2×200 mL). The organic phase was washed with NaHCO3 (aq.), dried (MgSO4) and evaporated under reduced pressure to afford the desired product (830 mg, 83%) as an off-white solid.

1. temperatureThe reaction mixture was cooled to 0° C.
2. temperatureto warm to ambient temperature over 2 h
3. customExcess sodium nitrite was destroyed by the addition of urea
4. additionThe resultant mixture was added to a solution of concentrated sulphuric acid (5.0 mL) in water (55 mL)
5. temperatureheated to 90° C.
6. filtrationThe resultant product mixture was filtered through dicalite
7. extractionextracted with dichloromethane (2×200 mL)
8. washThe organic phase was washed with NaHCO3 (aq.)
9. dry with materialdried (MgSO4)
10. customevaporated under reduced pressure

ORD-Eintrag

ord-eaa5c20ec47b41b49f975615ab80de95

Quelldatensatz

uspto-grants-2011_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07868017B2