N-Iodosuccinimide → 5-(2-hydroxyethyl)-6-iodo-2-benzofuran-1(3H)-one

HRID 1848417Notes

Reaction equation

[OH:1][CH2:2][CH2:3][C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1.C1C(=O)N([I:21])C(=O)C1>S(O)(C(F)(F)F)(=O)=O>[OH:1][CH2:2][CH2:3][C:4]1[C:13]([I:21])=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[CH:5]=1.[OH:1][CH2:2][CH2:3][C:4]1[CH:13]=[CH:12][C:7]2[C:8](=[O:11])[O:9][CH2:10][C:6]=2[C:5]=1[I:21]

Participants

Conditions

Temperature: 0 °C

Procedure

To a cooled (0° C.) solution of 5-(2-hydroxyethyl)-2-benzofuran-1(3H)-one (9.00 g, 50.6 mmol) in 100 mL of TfOH was added NIS (12.5 g, 55.6 mmol), then the mixture was stirred at 0° C. for 2 hrs and then poured into ice-water (500 mL). The solution was extracted three times with 500 mL of EtOAc and the combined organic layers were washed with saturated NaHCO3 and brine, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by column chromatography (EtOAc/Petrol Ether=1:5) to give the desired 5-(2-hydroxyethyl)-6-iodo-2-benzofuran-1(3H)-one and regioisomer by-product 5-(2-hydroxyethyl)-4-iodo-2-benzofuran-1(3H)-one. 1H-NMR (400 MHz, CDCl3) δ ppm 7.84 (d, J=7.8 Hz, 1H), 7.46 (d, J=7.8 Hz, 1H), 5.09 (s, 2H), 3.93 (q, J=6.3 Hz, 2H), 3.16 (t, J=6.3 Hz, 2H), 1.45 (t, J=5.5 Hz, 1H).

Workup

extractionThe solution was extracted three times with 500 mL of EtOAc
washthe combined organic layers were washed with saturated NaHCO3 and brine
dry with materialdried over anhydrous sodium sulfate
filtrationfiltered
concentrationconcentrated
customThe residue was purified by column chromatography (EtOAc/Petrol Ether=1:5)

Sources & evidence

ORD record: ord-6d186634bdc4402389b39557e97db330
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952166B2

Reaction notes

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