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 as trifluoroacetic anhydride (500 mL) followed by the addition of 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 (I-1a) as an off-white solid.

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

ORD record

ord-37f553d48af84ba6877e566ee9f35b5c

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07618996B2