Hydrochloric Acid → 3-Methoxybenzoic Acid

Temperature

40 °C

A 1 N solution of NaOH (6.15 mL; 6.14 mmol) was added dropwise to a solution of 4-(aminomethyl)-3-methoxybenzoic acid methyl ester C (1.2 g; 6.14 mmol) in MeOH (25 mL) heated at 40° C. After stirring 8 h at 45° C. the solution was stirred over night at room temperature. A 1 N solution of NaOH (0.6 mL; 0.6 mmol) was added and the mixture heated at 40° C. for 4 h. The solution was concentrated, acidified with 1 N HCl (8 mL; 8 mmol), extracted with EtOAc (2×10 mL) then the aqueous layer was concentrated to 15 mL. This solution (pH 4.5) was cooled at 0° C. and Et3N (936 μL; 6.75 mmol) was added (pH 11). A solution of N-(9-fluorenylmethoxycarbonyloxy)succinimide (3.04 g; 9 mmol) in MeCN (30 mL) was added dropwise (final pH 9) and a white solid precipitated. After stirring 1 h at room temperature the solid was filtered, suspended in 1N HCl (15 mL) and the suspension was stirred for 30 min. The solid was filtered to provide 4-[[[9H-fluoren-9-ylmethoxy)carbonyl]amino]methyl]-3-methoxybenzoic acid E as a white solid (275 mg; 0.7 mmol).

1. stirringwas stirred over night at room temperature
2. temperaturethe mixture heated at 40° C. for 4 h
3. concentrationThe solution was concentrated
4. extractionextracted with EtOAc (2×10 mL)
5. concentrationthe aqueous layer was concentrated to 15 mL
6. temperatureThis solution (pH 4.5) was cooled at 0° C.
7. customprecipitated
8. stirringAfter stirring 1 h at room temperature the solid
9. filtrationwas filtered
10. stirringthe suspension was stirred for 30 min
11. filtrationThe solid was filtered

ORD record

ord-c58d29ebc8b546ceafeca6cf223a2c7a

Source dataset

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07850947B2