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Methanesulfonylation of BOC protected (S)-Alaninol; (S)-2-(tert-butoxycarbonylamino)propyl methanesulfonate

SyntheticPage 615
DOI: 10.1039/SP615
Submitted Jul 11, 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" alt="" />Methanesulfonylation of BOC protected (<em>S</em>)-Alaninol<img src="/images/empty.gif" alt="" />

Chemicals Used

Methanesulfonyl chloride (Fluka)
(S)-tert-butyl 1-hydroxypropan-2-ylcarbamate (Prepared in house, see page 614)
Dichloromethane (Fisher Scientific)
Triethylamine (BDH)

Procedure

A solution of methanesulfonyl chloride (0.93 ml, 12 mmol) in DCM (20 ml) was added dropwise over 30 min to a solution of (S)-tert-butyl 1-hydroxypropan-2-ylcarbamate (2.0 g, 11 mmol) and TEA (1.8 ml, 12.5 mmol) in DCM (40 ml). The volatiles were then removed under reduced pressure and the residue was redissolved in ethyl acetate (30 ml) and water (30 ml). The organic layer was washed with an aqueous solution of NaHCO3 (30 ml, 5%), brine (30 ml) and dried over anhydrous Na2SO4. The product was obtained upon removal of the solvent under reduced pressure. Yield 2.1 g (75%).

Author's Comments

Product was sufficiently clean to carry on to next step without resort to column chromatography. See NMR.

Data

1H NMR (400 MHz, 298 K, CDCl3) δH 4.61 (1H, br s, NH), 4.21 (1H, br s, CH2), 4.15 (1H, br s, 3JHH = 10.0 Hz, 2JHH = 4.3 Hz, CH2), 4.05 – 3.90 (1H, br s, CH), 3.02 (3H, s, SO3CH3), 1.44 (9H, s, tBu), 1.22 (3H, d, 3JHH = 6.9 Hz, CHCH3).

13C NMR (100 MHz, 298 K, CDCl3) δC 155.22 (C=O), 72.17 (CH2), 45.65 (CH), 37.45 (SO3CH3), 28.45 (C(CH3)3), 17.30 (CHCH3), no quaternary carbon peak found

MS (ESI+) m/z 276.1 ([M+Na]+)

IR (cm-1) ν 3358, 2978, 2937, 1687, 1527, 1463, 1430, 1394, 1368, 1347, 1331, 1301, 1279, 1242, 1159, 1109, 1061, 1031, 996, 972, 941, 927, 900, 850, 812, 779, 743.


Lead Reference

K. Higashiura, H. Morino, H. Matsuura, Y. Toyomaki and K. Ienaga, J. Chem. Soc., Perkin Trans. 1, 1989, 1479-1481.http://dx.doi.org/10.1039/p19890001479

Supplementary Information

1H NMR (1H NMR.jcamp)

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

Keywords: addition, alcohols, BOC protected, esters, methanesulfonylation

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