3,5-Dichlorobenzoic acid → 3',5'-Dichloroacetophenone

Temperature

0 °C

3,5-Dichlorobenzoic acid (19,10 g, 100 mmol) was dissolved in dry THF (165 mL) and cooled to 0° C. in an ice bath. With vigorous stirring, 138 mL (210 mmol) of methyl lithium (1.6 M in diethyl ether) was added dropwise over a period of 30 min via syringe. After 1 hour the mixture was poured into ice-water (500 mL). The aqueous phase was extracted with diethyl ether (4×50 mL). The combined organic phases were washed with saturated aqueous sodium hydrogen carbonate (2×50 mL) and saturated aqueous sodium chloride (2×50 mL). The organic phase was dried (magnesium sulphate), filtered and the solvent was removed in vacuo. This afforded 17.06 g of the title compound containing 18% by weight of 2-(3,5-dichlorophenyl)propan-2-ol. This compound was used in the next step without further purification.

1. extractionThe aqueous phase was extracted with diethyl ether (4×50 mL)
2. washThe combined organic phases were washed with saturated aqueous sodium hydrogen carbonate (2×50 mL) and saturated aqueous sodium chloride (2×50 mL)
3. dry with materialThe organic phase was dried (magnesium sulphate)
4. filtrationfiltered
5. customthe solvent was removed in vacuo
6. additionThis afforded 17.06 g of the title compound containing 18% by weight of 2-(3,5-dichlorophenyl)propan-2-ol
7. customThis compound was used in the next step without further purification

ORD record

ord-dbf7163c4be7482ba7c2d3a09a6b8bc8

Source dataset

uspto-grants-2004_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06762318B2