ChemicalBook CAS DataBase List Boc-L-Threonine

Boc-L-Threonine synthesis

9synthesis methods

Product Name:Boc-L-Threonine
CAS Number:2592-18-9
Molecular formula:C9H17NO5
Molecular Weight:219.24

72-19-5

24424-99-5

2592-18-9

The general procedure for the synthesis of (2S,3R)-2-((tert-butoxycarbonyl)amino)-3-hydroxybutyric acid from L-threonine and di-tert-butyl dicarbonate was as follows: 1. To a methanol (5 mL) solution of L-threonine (400 mg, 3.36 mmol), a water (5 mL) solution of sodium bicarbonate (434 mg, 5.17 mmol) was added, followed by di-tert-butyl dicarbonate (1.07 g, 4.90 mmol). 2. The reaction mixture was stirred at room temperature for 3 days. 3. Upon completion of the reaction, the solvent was removed by vacuum distillation. 4. 4. The residue was diluted with water (20 mL) and washed with ether (2 x 20 mL). 5. The aqueous layer was acidified with saturated aqueous sodium bisulfite and then extracted with 2-methyltetrahydrofuran. 6. The organic layer was dried over anhydrous sodium sulfate and subsequently concentrated in vacuo to afford the title compound (2S,3R)-2-((tert-butoxycarbonyl)amino)-3-hydroxybutyric acid as a white solid (730 mg, 99% yield). 7. The product was characterized by 1H NMR (400 MHz, CDCl3) and LC-MS: 1H NMR δ 1.24 (d, 3H), 1.44 (s, 9H), 4.26 (d, 1H), 4.40 (d, 1H), 5.52 (d, 1H), 5.69 (br s, 1H); LCMS Rt = 1.68 min, MS m/z 218 [M + H]+.

72-19-5 Synthesis

72-19-5
789 suppliers
$4.76/25g

24424-99-5 Synthesis

24424-99-5
860 suppliers
$13.50/25G

2592-18-9
330 suppliers
$5.00/1g

Yield:2592-18-9 99%

Reaction Conditions:

with sodium hydrogencarbonate in methanol;water at 20; for 72 h;

Steps:

52 Preparation 52
Preparation 52 N-Boc-L-threonine To a solution of L-threonine (400 mg, 3.36 mmol) in MeOH (5 mL) was added NaHCO₃ (434 mg, 5.17 mmol) in water (5 mL) followed by Boc₂O (1 .07 g, 4.90 mmol) and the reaction stirred at room temperature for 3 days. The solvent was removed in vacuo and the residue diluted with water (20 mL) and washed with ether (2 x 20 mL). The aqueous layer was acidified with saturated aqueous NaHSO solution and extracted with 2-MeTHF. The organic layer was dried over Na₂SO and concentrated in vacuo to afford the title compound as a white solid (730 mg, 99%). 1H NMR (400MHz, CDCI₃): δ ppm 1 .24 (d, 3H), 1 .44 (s, 9H), 4.26 (d, 1 H), 4.40 (d, 1 H), 5.52 (d, 1 H), 5.69 (br s, 1 H). LCMS Rt = 1 .68 minutes MS m/z 218 [M+H]⁺

References:

PFIZER INC.;BAGAL, Sharanjeet Kaur;BROWN, Alan Daniel;KEMP, Mark Ian;KLUTE, Wolfgang;MARRON, Brian Edward;MILLER, Duncan Charles;SKERRATT, Sarah Elizabeth;SUTO, Mark J.;WEST, Christopher William;MALET SANZ, Laia WO2013/114250, 2013, A1 Location in patent:Page/Page column 161; 162

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