Imidazole → 1,1-dimethylethyl (4R)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-5-iodopentanoate

To a solution of crude 1,1-dimethylethyl (4R)-4-({[(1,1-dimethylethyl)oxy]carbonyl}amino)-5-hydroxypentanoate (23.8 g, 82.4 mmol), triphenylphosphine (32.42 g, 123.6 mmol) and imidazole (8.41 g, 123.6 mmol) in 515 mL anhydrous CH2Cl2 under N2 at 0° C. was added iodine over 15 min portionwise. The ice bath was removed and the reaction was allowed to warm to room temperature and stirred over 30 minutes. The reaction was quenched with 200 mL H2O. The aqueous layer was extracted with diethyl ether (2×150 mL). The combined organic layers were washed with sat. aq. Na2SO3 solution (2×25 mL) and brine (25 mL), dried over MgSO4, and concentrated in vacuo. Purification of the residue by silica gel chromatography (Analogix IF280, 5%-50% EtOAc/Hex) afforded the title compound as a white solid (25.34 g, 77%). ESMS [M+H]+=400.4.

1. customThe ice bath was removed
2. customThe reaction was quenched with 200 mL H2O
3. extractionThe aqueous layer was extracted with diethyl ether (2×150 mL)
4. washThe combined organic layers were washed with sat. aq. Na2SO3 solution (2×25 mL) and brine (25 mL)
5. dry with materialdried over MgSO4
6. concentrationconcentrated in vacuo
7. customPurification of the residue by silica gel chromatography (Analogix IF280, 5%-50% EtOAc/Hex)

ORD record

ord-dfd0bb9d79f74103b19a68e3b8340500

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07618981B2