Allyl bromide → HCID 53916592, compound

Temperature

-45 °C

To a stirred, cold (−78° C.) solution of (2R)-2-benzyloxycarbonylamino-pentanedioic acid 1-tert-butyl ester 5-methyl ester (5.6 g, 15.9 mmol), prepared as described in J. Org. Chem., 55, 1711-1721 (1990) and J. Med. Chem., 39, 73-85 (1996), in 30 mL of tetrahydrofuran was added lithium bis(trimethylsilyl)amide (40 mL, 1 M in tetrahydrofuran, 39.8 mmol). The resulting mixture was stirred for 1 hour at −45° C. and then recooled to −78° C. Allyl bromide (5.2 mL, 63.7 mmol) was then added. After 2 hours the reaction was quenched by the addition of 1 M aqueous hydrogen chloride at −78° C. The mixture was then extracted with diethyl ether. The combined ethereal extracts were washed with brine and the mixture was dried over sodium sulfate. After filtration and concentration of the filtrate, the crude product was purified by silica gel chromatography (elution with 1:5 ethyl acetate/hexanes) to provide (2R,4R)-4-allyl-2-benzyloxycarbonylamino-pentanedioic acid 1-tert-butyl ester 5-methyl ester.

1. customrecooled to −78° C
2. customAfter 2 hours the reaction was quenched by the addition of 1 M aqueous hydrogen chloride at −78° C
3. extractionThe mixture was then extracted with diethyl ether
4. washThe combined ethereal extracts were washed with brine
5. dry with materialthe mixture was dried over sodium sulfate
6. filtrationAfter filtration and concentration of the filtrate
7. customthe crude product was purified by silica gel chromatography (elution with 1:5 ethyl acetate/hexanes)

ORD record

ord-704a139c05fb490b956e1f1cc733f4d3

Source dataset

uspto-grants-2003_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06599890B1