4-Methylmorpholine → N-[4-(Hydroxymethyl)phenyl]-N-methylacetamide

Temperatur

-20 °C

An oven dried flask, under nitrogen flow, was charged with a stir bar, 4-(N-acetyl-N-methyl-amino)benzoic acid (1.0 g, 5.18 mmol), prepared as in step7, anhydrous DME (10.3 mL), and anhydrous DMF (3.0 mL). The resulting solution was cooled to -20° C., and 4-methylmorpholine (0.60 mL, 5.4 mmol) and isobutyl chloroformate (0.70 mL, 5.4 mmol) were added sequentially via syringe. The reaction mixture was stirred under N2 at -20° C. for 1 hour. The resultant yellow mixture was filtered and the precipitate washed with DME (2×, ~1 mL). The combined filtrate and washings were cooled to 0° C. and sodium borohydride (800 mg, 21.1 mmol) dissolved in water (2.0 mL) was added dropwise. The reaction was stirred at 0° C. for 15 min. and quenched with saturated aqueous ammonium chloride. The resulting mixture was partitionedbetween ethyl acetate and brine. The combined organic layers were dried (MgSO 4), filtered and concentrated in vacuo to give an oil. Purification by flash chromatography on silica gel (90% ethyl acetate/hexane) provided 4-(N-acetyl-N-methyl-amino)benzyl alcohol as a colorless oil which solidified on standing. Recrystallization from hexane provided the alcohol as a colorless solid (543.0 mg, 58.5%). 1H NMR (300 MHz, CDCl3) d 7.45 (2H, d, J=8.5 Hz), 7.18 (2H, d, J=8.5 Hz), 4.75 (2H, s), 3.27 (3H, s), 1.90 (3H, br s). MS m/e 180 (M+H)+, 197 (M+NH4)+.

1. customAn oven dried flask
2. additionunder nitrogen flow, was charged with a stir bar
3. filtrationThe resultant yellow mixture was filtered
4. washthe precipitate washed with DME (2×, ~1 mL)
5. temperatureThe combined filtrate and washings were cooled to 0° C.
6. additionwas added dropwise
7. stirringThe reaction was stirred at 0° C. for 15 min.
8. customquenched with saturated aqueous ammonium chloride
9. dry with materialThe combined organic layers were dried (MgSO 4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo
12. customto give an oil
13. customPurification by flash chromatography on silica gel (90% ethyl acetate/hexane)

ORD-Eintrag

ord-e14a4690f355456cb6dc38df1d244fbb

Quelldatensatz

uspto-grants-1995_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05446062