Dimethyl Sulfoxide → 4-Chloro-2-(trifluoromethyl)phenol

To a 300 ml, 3-necked flask fitted with a stirrer, condenser, thermometer and drying tube is added dimethylsulfoxide (100 ml), tert-butanol (20 ml), powdered potassium hydroxide (KOH) pellets (85%, 30 g) and 2,5-dichlorobenzotrifluoride (21.5 g, 0.10 mole). The reaction mixture is warmed to 71°-73° C. for 60 hours, then additional KOH (10 g) is added and heating is continued at 73°-75° C. for 24 hours. The reaction mixture is cooled and the solvent partially removed by distillation at 0.9 mm, bp 55° C.). The cooled pot residue is then poured into ice water (1000 g) which had been preacidified to pH 1 with conc. HCl (50 ml). The aqueous mixture is extracted with carbon tetrachloride (CCl4), the CCl4 layer decanted and dried and the solvent removed under vacuum to afford 10.8 g of 4-chloro-2-trifluoromethylphenol, which is sublimed to afford pure product, mp 81°-81.5° C. Elemental Anal. Calcd for C7H4ClF3O: C, 42.75; H, 2.06; Cl, 18.04: Found: C, 42.54; H, 2.36; Cl, 18.16. ##STR14##

1. customTo a 300 ml, 3-necked flask fitted with a stirrer, condenser
2. customthermometer and drying tube
3. temperatureThe reaction mixture is warmed to 71°-73° C. for 60 hours
4. temperatureheating
5. temperatureThe reaction mixture is cooled
6. customthe solvent partially removed by distillation at 0.9 mm, bp 55° C.)
7. additionThe cooled pot residue is then poured into ice water (1000 g) which
8. extractionThe aqueous mixture is extracted with carbon tetrachloride (CCl4)
9. customthe CCl4 layer decanted
10. customdried
11. customthe solvent removed under vacuum

ORD record

ord-b3944bc9fdd2400d96a6bb872e459c72

Source dataset

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04259510