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

HRID 1501735Notes

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-aa6b0a11a30448bd8688245b2a1f4eea
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09206198B2

Reaction notes

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