Methanol → 4-(6-Hydroxyhexyloxy)cinnamic acid

To a 1L round-bottom flask were added 3-[4-(6-Hydroxy-hexyloxy)-phenyl]-acrylic acid methyl ester (27.82 g, 100 mmol) and MeOH (250 mL) and H2O (80 mL) to render a yellow solution. KOH pellets (8.42 g, 150 mmol) was added in portions. The resulting solution was placed in an oil bath at 50° C. under N2 after the flask was equipped with a water condenser. After 24 h, HPLC analysis indicated more than 95% conversion. The solution was concentrated by rotary evaporation to remove most organic solvent. The remaining solution was diluted with ice cold H2O (400 mL) and cooled in an ice bath. Upon vigorous stirring, concentrated HCl solution (ca. 12 mL) was added dropwise to result in a white slurry (pH 3). The slurry was filtered with a Büchner funnel and the solid was rinsed with additional H2O (ca. 500 mL) and then transferred to a recrystallization dish. After drying overnight in the air, the solid was transferred to an amber bottle, cooled in a dry ice box for 1 h and then lyophilized for 16 h. The hydroxy acid weighed 24.9 g (94% yield).

1. additionwas added in portions
2. customThe resulting solution was placed in an oil bath at 50° C. under N2
3. customafter the flask was equipped with a water condenser
4. concentrationThe solution was concentrated by rotary evaporation
5. customto remove most organic solvent
6. additionThe remaining solution was diluted with ice cold H2O (400 mL)
7. temperaturecooled in an ice bath
8. additionUpon vigorous stirring, concentrated HCl solution (ca. 12 mL) was added dropwise
9. customto result in a white slurry (pH 3)
10. filtrationThe slurry was filtered with a Büchner funnel
11. washthe solid was rinsed with additional H2O (ca. 500 mL)
12. customAfter drying overnight in the air
13. temperaturecooled in a dry ice box for 1 h
14. waitlyophilized for 16 h

ORD record

ord-e19e5f602c294ce0b6acb92409bf14f1

Source dataset

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08362151B2