Imidazole → 2-Methyl-2-propanyl (3R)-4-iodo-3-({[(2-methyl-2-propanyl)oxy]carbonyl}amino)butanoate

Triphenylphosphine (1.07 g, 4 mmol), imidazole (277 mg, 4 mmol) and iodine (1.02 g, 4 mmol) were dissolved into methylene chloride (12 mL) under nitrogen atmosphere. (R)-tert-butyl 3-(tert-butoxycarbonylamino)-4-hydroxybutanoate (275 mg, 1 mmol) was dissolved into methylene chloride (4 mL) and added dropwise to the solution. After 1 h, methylene chloride (100 mL) was added and the solution was filtered through celite. The filtrate was washed with 1% sodium bisulfite solution (2×10 mL), brine (20 mL), dried over MgSO4 and concentrated to dryness. The residue was purified by silica gel chromatography (ethyl acetate/hexanes 1:1) to give the title compound (225 mg, 58%) as a white solid. 1H NMR (300 MHz, DMSO-d6) δ 7.05-6.95 (m, 1H), 4.04-3.97 (m, 1H), 3.77-3.65 (m, 2H), 2.55-2.50 (m, 1H), 2.38-2.27 (m, 1H), 1.39 (s, 9H), 1.36 (s, 9H).

1. additionadded dropwise to the solution
2. filtrationthe solution was filtered through celite
3. washThe filtrate was washed with 1% sodium bisulfite solution (2×10 mL), brine (20 mL)
4. dry with materialdried over MgSO4
5. concentrationconcentrated to dryness
6. customThe residue was purified by silica gel chromatography (ethyl acetate/hexanes 1:1)

ORD record

ord-29bce019f17e4723beebf191977840b0

Source dataset

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08410150B2