ChemicalBook CAS DataBase List N-Boc-4-oxo-L-Proline methyl ester

N-Boc-4-oxo-L-Proline methyl ester synthesis

9synthesis methods

Product Name:N-Boc-4-oxo-L-Proline methyl ester
CAS Number:102195-80-2
Molecular formula:C11H17NO5
Molecular Weight:243.26

74844-91-0 Synthesis

N-Boc-trans-4-Hydroxy-L-proline methyl ester

74844-91-0
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102195-80-2
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$5.00/250mg

Yield:102195-80-2 98.17%

Reaction Conditions:

with 2,2,6,6-Tetramethyl-1-piperidinyloxy free radical;trichloroisocyanuric acid in dichloromethane at 0 - 20; for 0.5 h;

Steps:

43.A Step A:
To a solution of N-Boc-trans-4-hydroxyl-L-methyl prolinate (114.00 g, 464.79 mmol) in dichloromethane (1.2 L) was added trichloroisocyanuric acid(113.42 g, 488.03 mmol) and then TEMPO (1.46 g, 9.30 mmol) was added at 0 °C.
After stirring for 0.5 h at 10-20 °C, the mixture was filtered with kieselguhr.
The dichloromethane phase was washed with sat. aq K₂CO₃ (1000 mL) twice, then with sat.aq NaCl (800 mL), dried over anhydrous Na₂SO₄, filtered and the filtrate was concentrated in vacuo to give N-Boc- 4-oxo-L-methyl prolinate (111.00 g, 456.30 mmol, 98.17%).
¹H NMR (CDCl₃, 400 MHz): δ 4.81-4.64 (m, 1H), 3.84 (d, J = 7.8 Hz, 2H), 3.73 (s, 3H), 2.99-2.84 (m, 1H), 2.55 (d, J = 20.0 Hz, 1H), 1.43 (d, J = 8.0 Hz, 9H).

References:

Medshine Discovery Inc.;SUN, Fei;DING, Charles Z.;CAI, Zhe;QIAN, Wenyuan;HU, Guoping;LI, Jian;CHEN, Shuhui EP3450430, 2019, A1 Location in patent:Paragraph 0272; 0273

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