L-Isoleucine → L-Isoleucine, N-(methoxycarbonyl)-

Temperature

60 °C

A solution of L-iso-Leucine (7.43 g, 56.6 mmol) in a mixture of dioxane (28 mL) and aqueous NaOH solution (93.5 mL, 2N) was treated with methyl chloroformate (8.75 mL, 113.3 mmol) dropwise, not allowing the internal temperature to rise above 50° C. The mixture was warmed to 60° C. and stirred for 18 hours, cooled to 25° C., and extracted with dichloromethane. The aqueous phase was cooled to 0° C., and its pH was adjusted to 1-2 with HCl (4 N). The mixture was partitioned between ethyl acetate and water, and the organic phase was washed with brine, dried over Na2SO4, filtered and concentrated to give the crude product (10 g).

1. customto rise above 50° C
2. temperaturecooled to 25° C.
3. extractionextracted with dichloromethane
4. temperatureThe aqueous phase was cooled to 0° C.
5. customThe mixture was partitioned between ethyl acetate and water
6. washthe organic phase was washed with brine
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated

ORD record

ord-348ecef9329d475aa5660367db8e1ab2

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07834043B2