Reacción #2175467

Ecuación de reacción

NaHCO3

hydrochloride salt

(2R)-2-Phenylcarbonyloxypropyl (2S)-2-amino-3-(3,4-dihydroxyphenyl)propanoate hydrochloride

Methanesulfonic acid

ethyl acetate

methanesulfonic acid

→

mesylate salt

Rendimiento 99.3%

(2R)-2-Phenylcarbonyloxypropyl (2S)-2-amino-3-(3,4-dihydroxyphenyl)propanoate mesylate

Rendimiento 99.3%

Disolventes

water

water

Condiciones de reacción

Tratamiento posterior

1. 1
   ExtracciónThe resulting aqueous suspension was extracted with ethyl acetate (EtOAc) (2×400 mL)
2. 2
   ExtracciónThe combined EtOAc extract
3. 3
   Lavadowas washed with water
4. 4
   Secadobrine, and dried through MgSO4
5. 5
   OtroWhite precipitate
6. 6
   Otroformed as
7. 7
   workup.STIRRINGThe suspension was stirred for another 30 min
8. 8
   Filtraciónfiltered
9. 9
   LavadoThe filter cake was washed three times with ethyl acetate (EtOAc) and vacuum
10. 10
    Otrodried overnight

Procedimiento

A solution of NaHCO3 (9.87 g, 117.5 mmol) in water (80 mL) was slowly added to a solution of hydrochloride salt 1d (31.0 g, 78.3 mmol) in water (300 mL). The resulting aqueous suspension was extracted with ethyl acetate (EtOAc) (2×400 mL). The combined EtOAc extract was washed with water, then brine, and dried through MgSO4. Methanesulfonic acid (6.04 mL, 93.12 mmol) was slowly added to the ethyl acetate (EtOAc) solution while stirred. White precipitate formed as soon as the addition of methanesulfonic acid was complete. The suspension was stirred for another 30 min and then filtered. The filter cake was washed three times with ethyl acetate (EtOAc) and vacuum dried overnight to afford 35.4 g (quantitative yield) of anhydrous mesylate salt 1 as a white solid. 1H NMR (400 MHz, CD3OD): δ 1.40 (d, J=6.4 Hz, 3H), 2.70 (s, 3H), 2.98 (dd, J=7.8, 14.6 Hz, 1H), 3.10 (dd, J=5.6, 14.4 Hz, 1H), 4.24 (dd, J=5.8, 7.8 Hz, 1H), 4.38 (dd, J=6.8, 12.0 Hz, 1H), 4.52 (dd, J=3.4, 11.8 Hz, 1H), 5.40 (dp, J=3.2, 6.4 Hz, 1H), 6.52 (dd, J=2.2, 8.2 Hz, 1H), 6.67 (d, J=2.2 Hz, 1H), 6.69 (d, J=8.0 Hz, 1H), 7.47 (t, J=7.6 Hz, 2H), 7.60 (br t, J=7.4 Hz, 1H), 8.01 (d, J=7.6 Hz, 2H). MS (ESI) m/z 360.07 (M+H)+ and 358.01 (M−H)−.

Fuente