Hydrochloric Acid → 1-Acetamido-3-chloropropan-2-yl acetate

Acetic anhydride (13 ml) is added to a thin slurry of (±)-1amino-3-chloro-2-propanol hydrochloride ((±)-V, EXAMPLE 5, 5.0110 g, 34.317 mmol) in pyridine (20 ml) while maintaining the temperature in the range of 20-50°. The mixture is stirred at 20-25° for 18 hours, then water (14 ml) is added with an exotherm to 65°. The mixture is concentrated under reduced pressure and water (50 ml) is added. The pH is adjusted to 0.89 with hydrochloric acid (37.7%, 1.467 g, 15.17 mmol, 0.442 eq) at 0°. The mixture is extracted with methylene chloride (4×50 ml), the extracts dried over sodium sulfate and concentrated under reduced pressure. Ethyl acetate (20 ml) and heptane (20 ml) are added, the mixture seeded, then heptane (40 ml) is added to the resultant slurry. The precipitate is collected by filtration with reduced pressure, washed with heptane and dried to give a the title compound, mp=68.0-69.5°; TLC (silica gel; ethyl acetate, iodine char) Rf=0.39 (one spot); NMR 2.00, 2.21, 3.52, 3.62, 3.70, 5.10 and 6.33 δ; CMR 20.93, 23.10, 40.47, 43.53, 71.95, 170.45 and 170.71 δ; MS (CI NH3) m/z (relative intensity) 213 (36), 211 (100), 196 (18) and 194 (53).

1. temperaturewhile maintaining the temperature in the range of 20-50°
2. concentrationThe mixture is concentrated under reduced pressure and water (50 ml)
3. additionis added
4. extractionThe mixture is extracted with methylene chloride (4×50 ml)
5. dry with materialthe extracts dried over sodium sulfate
6. concentrationconcentrated under reduced pressure
7. additionEthyl acetate (20 ml) and heptane (20 ml) are added
8. additionheptane (40 ml) is added to the resultant slurry
9. filtrationThe precipitate is collected by filtration with reduced pressure
10. washwashed with heptane
11. customdried

ORD-Eintrag

ord-9042db66a4f948318a80833a8d5fc23f

Quelldatensatz

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06613944B2