Acetone → 7-hydroxy-2,2-dimethyl-4H-benzo[d][1,3]dioxin-4-one

A suspension of 2,4-dihydroxybenzoic acid (85.0 g) in trifluoroacetic acid (800 mL) was cooled in an ice/water bath. Trifluoroacetic anhydride (500 mL) was added followed by acetone (100 mL). After the addition was complete, the ice/water bath was removed and the reaction mixture stirred for 24 hours before the volatiles were removed under vacuum using a rotary evaporator. The residue was cautiously added to a water/sodium bicarbonate suspension to afford a neutralized mixture. The mixture was extracted with ethyl acetate and the combined organic phases were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was triturated with dichloromethane to afford the product as an off-white solid (50 g).

1. temperaturewas cooled in an ice/water bath
2. additionAfter the addition
3. customthe ice/water bath was removed
4. customwere removed under vacuum
5. customa rotary evaporator
6. additionThe residue was cautiously added to a water/sodium bicarbonate suspension
7. customto afford a neutralized mixture
8. extractionThe mixture was extracted with ethyl acetate
9. washthe combined organic phases were washed with brine
10. dry with materialdried over magnesium sulfate
11. filtrationfiltered
12. customevaporated
13. customThe residue was triturated with dichloromethane

ORD record

ord-361295f64ad54057b7dc1b2b61ea4940

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09045440B2