Methylparaben → Methyl 4-(2-aminoethoxy)benzoate

To a cooled (0° C.) solution of 2-(N-tert-butoxycarbonylamino)ethanol (3.20 g, 19.9 mmol), methyl 4-hydroxybenzoate (3.02 g, 19.9 mmol) and Ph3P (6.25 g, 23.8 mmol) in THF (50 ml) was added dropwise DIAD (4.69 ml, 23.8 mmol) over for 5 min. The reaction mixture was heated under reflux for 3 hr. The mixture was evaporated and the residue was dissolved in CH2Cl2 (30 ml) and TFA (30 ml). The reaction mixture was stirred at room temperature overnight. The mixture was concentrated in vacuo and the residue was dissolved in CHCl3 and H2O. The solution was made basic by sat. NaHCO3 and extracted with CHCl3. The extract was washed with brine, dried over Na2SO4 and evaporated. The residue was purified by column chromatography on silica-gel with CHCl3—MeOH (30:1, v/v) as eluent to give methyl 4-(2-aminoethoxy)benzoate (1.03 g, 34% for 2 steps) as a colorless oil. 1H-NMR (CDCl3) δ3.10-3.13 (m, 2 H), 3.89 (s, 3 H), 4.03-4.06 (m, 2 H), 6.92-6.94 (m, 2 H), 7.98-8.00 (m, 2 H).

1. temperatureThe reaction mixture was heated
2. temperatureunder reflux for 3 hr
3. customThe mixture was evaporated
4. dissolutionthe residue was dissolved in CH2Cl2 (30 ml)
5. concentrationThe mixture was concentrated in vacuo
6. dissolutionthe residue was dissolved in CHCl3
7. extractionextracted with CHCl3
8. washThe extract was washed with brine
9. dry with materialdried over Na2SO4
10. customevaporated
11. customThe residue was purified by column chromatography on silica-gel with CHCl3—MeOH (30:1

ORDレコード

ord-083702da1bd448d7b65ced5ced7f5736

出典データセット

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US06756378B2