Ethanol → 2-Amino-3-methoxybenzaldehyde

Iron powder (40 g) was slowly added to a stirred solution of 3-methoxy-2-nitrobenzaldehyde (1) (70 g, 386 mmole) in AcOH gal. (100 mL) and EtOH abs. (400 mL). The reaction was cooled using an ice bath followed by addition of con. HCL (1 mL). The reaction became exothermic. After stabilization of the reaction temperature, the reaction was heated to reflux. The reaction reached completion after ca. 20 minutes according to LCMS. The reaction mixture was cooled to RT and filtered. The filtrate was evaporated to a thick brown syrup. The dark residue was dissolved in EtOAc (500 mL) and water (200 mL). The mixture was basified with NaOH 6M to ca. pH 10. The mixture was filtered over celite and the layers separated. The organic layer was washed with NaHCO3 (2×100 mL), water (2×100 mL), brine (100 mL), dried (Na2SO4), filtered and evaporated to a dark amber oil. The oil was dried in vacuo to give 95% pure product 2-amino-3-methoxybenzaldehyde in 64% yield (37.2 g, 246 mmole).

1. temperatureThe reaction was cooled
2. additionfollowed by addition of con
3. temperatureAfter stabilization of the reaction temperature, the reaction was heated to reflux
4. customafter ca. 20 minutes
5. filtrationfiltered
6. customThe filtrate was evaporated to a thick brown syrup
7. dissolutionThe dark residue was dissolved in EtOAc (500 mL)
8. filtrationThe mixture was filtered over celite
9. customthe layers separated
10. washThe organic layer was washed with NaHCO3 (2×100 mL), water (2×100 mL), brine (100 mL)
11. dry with materialdried (Na2SO4)
12. filtrationfiltered
13. customevaporated to a dark amber oil
14. customThe oil was dried in vacuo

ORD record

ord-62466dc451b941a69549c17c8c998211

Source dataset

uspto-grants-2011_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07932262B2