Chloride → 2-Hydroxy-3',4'-dihydroxyacetophenone

Temperature

100 °C

A 1 liter reactor equipped with a reflux condenser and magnetic stirring bar was charged under argon with 50.5 g of 4-chloroacetyl-catechol of a purity of ca. 99%, 500 ml of water, 28 g of sodium formate and 15.5 ml (˜19 g) of formic acid. The stirred mixture was heated under reflux (˜100° C.) for 22 hours. The solution was cooled to about 25° C. and acidified by addition of 36.6 g of conc. hydrochloric acid (37%) resulting in a pH of about 0.5. The mixture was extracted with ethyl acetate, once with 1 l then 3 times with 0.5 l each. The organic extracts have been back washed 3 times with 300 ml 10% brine. The combined organic phases were dried with sodium sulfate, filtered and evaporated at reduced pressure at 40° C. and dried at 45° C. at ˜0.5 mbar. This resulted in a light tan solid crystalline product of 44.63 g of 96.4% purity corresponding to a yield of 95.9%. Analyses showed this material to have a contamination of 0.12% sodium ions and 0.03% chloride ions.

1. customA 1 liter reactor equipped with a reflux condenser and magnetic stirring bar
2. temperatureThe stirred mixture was heated
3. temperatureThe solution was cooled to about 25° C.
4. customresulting in a pH of about 0.5
5. extractionThe mixture was extracted with ethyl acetate, once with 1 l
6. washThe organic extracts have been back washed 3 times with 300 ml 10% brine
7. dry with materialThe combined organic phases were dried with sodium sulfate
8. filtrationfiltered
9. customevaporated at reduced pressure at 40° C.
10. customdried at 45° C. at ˜0.5 mbar
11. customThis resulted in a light tan solid crystalline product of 44.63 g of 96.4% purity corresponding to a yield of 95.9%

ORD record

ord-fac2a74624984bbab29d801a4591be90

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08017815B2