3-(allyloxy)benzaldehyde → 2-Allyl-3-hydroxybenzaldehyde

Temperature

217 °C

In a 500 ml three-necked Morton flask equipped with mechanical stirrer, thermometer and reflux condenser was added 100 g of 3-allyloxybenzaldehyde (0.62 moles, 1 eq.) and 150 g of cis/trans decalin (1.5 vol). The mixture was purged with nitrogen and then heated to a reflux temperature of 217° C. The reaction was maintained at this reflux temperature for seven hours then cooled and 231 mL of toluene was added. The reaction mixture was then allowed to cool to room temperature. After stirring for 18 hours and further cooling to 0-5° C., reaction mixture was filtered and the cake washed with 200 mL of heptane. The wet cake was stirred in 200 mL of heptane for 1-2 hours at room temperature. After filtration and drying of the cake at 40° C., 54.27 g of crude 2-allyl-3-hydroxybenzaldehyde were obtained. This represents a recovery of 82% of the available 2-allyl product produced by the Claisen rearrangement.

1. customIn a 500 ml three-necked Morton flask equipped with mechanical stirrer
2. temperaturethermometer and reflux condenser
3. customThe mixture was purged with nitrogen
4. temperatureThe reaction was maintained at this reflux temperature for seven hours
5. temperaturethen cooled
6. addition231 mL of toluene was added
7. temperatureto cool to room temperature
8. temperaturefurther cooling to 0-5° C.
9. customreaction mixture
10. filtrationwas filtered
11. washthe cake washed with 200 mL of heptane
12. stirringThe wet cake was stirred in 200 mL of heptane for 1-2 hours at room temperature
13. filtrationAfter filtration
14. customdrying of the cake at 40° C.

ORD record

ord-3b9fee1aecac4383acc59a94700d5628

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09029607B2