Methanesulfonyl chloride → (R)-2-((tert-butoxycarbonyl)amino)propyl methanesulfonate

Temperature

0 °C

A solution of 22.0 gm (125.6 mMol) (R)-N-tert-butoxycarbonyl-2-amino-1-propanol and 19.5 gm (150.7 mmol) diisopropylethylamine in 450 mL dichloromethane was cooled to 0° C. To this solution was added dropwise 10.7 mL (138.2 mMol) methanesulfonyl chloride at a rate to maintain the temperature of the reaction mixture at from 0° C. to 10° C. Once the addition was complete the reaction mixture was stirred at 0° C. for about one hour. The reaction mixture was washed twice with 200 mL portions of water, once with 200 mL saturated aqueous sodium chloride, dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel chromatography, eluting with 1:1 hexane:ethyl acetate. Fractions containing product were combined and concentrated under reduced pressure. The residue was crystallized from hexane and ethyl acetate to provide 19.4 gm (61%) of the desired compound in two crops (m.p.=65–68° C.)

1. temperatureto maintain the temperature of the reaction mixture at from 0° C. to 10° C
2. additionOnce the addition
3. washThe reaction mixture was washed twice with 200 mL portions of water, once with 200 mL saturated aqueous sodium chloride
4. dry with materialdried over magnesium sulfate
5. concentrationconcentrated under reduced pressure
6. washeluting with 1:1 hexane
7. additionFractions containing product
8. concentrationconcentrated under reduced pressure
9. customThe residue was crystallized from hexane and ethyl acetate

ORD record

ord-14339606a57845d788e375d251ca96ce

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07045545B1