Print version Print setup

Iodination of BOC protected phenylglycinol; (R)-Tert-butyl 2-iodo-1-phenylethylcarbamate

SyntheticPage 612
DOI: 10.1039/SP612
Submitted Jul 10, 2013, published Jul 15, 2013
Nikola P. Chmel (N.Chmel@warwick.ac.uk), Pratik Gurnani (pratik.gurnani@warwick.ac.uk)
A contribution from Scott group, Warwick University


			Reaction Scheme: <IMG src="/images/empty.gif">Iodination of BOC protected phenylglycinol<IMG src="/images/empty.gif">

Chemicals Used

(R)-tert-butyl 2-hydroxy-1-phenylethylcarbamate (Prepared in house, see page 611)
Imidazole (Aldrich)
Triphenylphosphine (Aldrich)
THF (Distilled over potassium)
Iodine (Acros)

Procedure

(R)-tert-butyl 2-hydroxy-1-phenylethylcarbamate (1.0 g, 4.2 mmol) was dissolved in dry THF (50 ml) under argon and cooled in an ice/water bath. Imidazole (1.06 g, 15.6 mmol), triphenylphosphine (2.91 g, 11.1 mmol) and iodine (2.72 g, 10.7 mmol) were added in that order. The resulting mixure was stirred for 1 h at 0°C and then at ambient temperature for 2 d. The reaction was quenched with a saturated solution of sodium thiosulphate (40 ml) and brine (40 ml). The aqueous layer was extracted with DCM (30 ml) and the combined organic layers were dried over anhydrous magnesium suphate. The solvents were removed under reduced pressure and the residue was purified on silica using DCM as eluent. Yield 0.85 g (58%).

Author's Comments

Although yield was modest it worked well and reproducibly.

Data

Elemental analysis found (calculated for C13H18NO2) %: 45.50 (44.97), H 5.35 (5.23), N 4.01 (4.03).

1H NMR (400 MHz, 298 K, CDCl3) δH 7.40 – 7.21 (5H, m, Ph), 5.04 (1H, s, NH), 4.78 (1H, s br, CH), 3.59 – 3.40 (2H, m, CH2), 1.43 (9H, s, tBu).

13C NMR (100 MHz, 298 K, CDCl3) δC 128.90, 128.17, 126.38 (Ph), 55.46 (CH), 28.48 (CH3), 12.33 (CH2).

MS (ESI+) m/z 370.0 ([M+Na]+)

IR (cm-1) ν 3354, 3009, 2981, 1688, 1521, 1453, 1417, 1392, 1368, 1351, 1333, 1316, 1279, 1247, 1155, 1123, 1079, 1044, 1020, 914, 877, 842, 758, 742, 698, 658.


Lead Reference

D. L. J. Clive, J. Peng, S. P. Fletcher, V. E. Ziffle and D. Wingert, Journal of Organic Chemistry, 2008, 73, 2330-2344. http://dx.doi.org/10.1021/jo7026307

Other References

R. Caputo, E. Cassano, L. Longobardo and G. Palumbo, Tetrahedron Letters, 1995, 36, 167-168.http://dx.doi.org/10.1016/0040-4039(94)02202-M

Supplementary Information

1H NMR (1H NMR.jcamp)
13C NMR (13C NMR.jcamp)

This page has been viewed approximately 1529 times since records began.

Get structure file (.cdx, .sk2, .mol)

Keywords: aromatics/arenes, esters, Iodination, substitution

Post new comment
Loading ...