Veratraldehyde → 1-(3,4-Dimethoxyphenyl)ethan-1-amine hydrochloride

Temperature

0 °C

3,4-Dimethoxybenzaldehyde (5.00 g, 30 mmol) was dissolved in anhydrous THF (10 mL) and the solution cooled in ice under an argon atmosphere. Lithium bis(trimethylsilyl)amide (1 M in THF, 36 mmol, 36 mL) was added drop-wise and the resulting mixture stirred at 0° C. for 30 min. Methylmagnesium bromide (1.4 M in THF, 2 equiv., 72 mmol, 43 mL) was added and the solution allowed to warm up to room temperature. It was then reflux for 24 h. The reaction mixture was then cooled to room temperature and poured into saturated aqueous NH4Cl (200 mL). The mixture was extracted twice with DCM (75 mL) and the extract dried over MgSO4. The solution was concentrated to a volume of about 25 mL under reduced pressure and diluted with an equal volume of Et2O. Excess hydrogen chloride (4 M in dioxane) was added, and the resulting precipitate collected by filtration. It was washed with Et2O and dried in vacuo. DL-3,4-Dimethoxy-α-methylbenzylamine hydrochloride (5.1 g, 78% yield) was obtained as an orange solid.

1. temperaturethe solution cooled in ice under an argon atmosphere
2. temperatureto warm up to room temperature
3. temperatureIt was then reflux for 24 h
4. temperatureThe reaction mixture was then cooled to room temperature
5. extractionThe mixture was extracted twice with DCM (75 mL)
6. dry with materialthe extract dried over MgSO4
7. concentrationThe solution was concentrated to a volume of about 25 mL under reduced pressure
8. additiondiluted with an equal volume of Et2O
9. additionExcess hydrogen chloride (4 M in dioxane) was added
10. filtrationthe resulting precipitate collected by filtration
11. washIt was washed with Et2O
12. customdried in vacuo

ORD record

ord-ddfa3e7fb2204511a29943d1c00b169d

Source dataset

uspto-grants-2002_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06448281B1