ChemicalBook CAS DataBase List Boc-L-aspartic acid 4-benzyl ester

Boc-L-aspartic acid 4-benzyl ester synthesis

6synthesis methods

Product Name:Boc-L-aspartic acid 4-benzyl ester
CAS Number:7536-58-5
Molecular formula:C16H21NO6
Molecular Weight:323.34

24424-99-5

2177-63-1

7536-58-5

The general procedure for the synthesis of (S)-4-(benzyloxy)-2-((tert-butoxycarbonyl)amino)-4-oxobutanoic acid from di-tert-butyl dicarbonate and L-aspartic acid-4-benzyl ester is as follows: in a round-bottomed flask, L-aspartic acid-4-benzyl ester (79.7 g, 357 mmol), sodium bicarbonate (60 g, 714.2 mmol), water (700 mL), and tetrahydrofuran (550 mL). The reaction system was cooled to 0 °C, followed by the slow addition of di-tert-butyl dicarbonate (105 g, 481 mmol) to the reaction vial. After the dropwise addition, the reaction was kept at 0 °C for half an hour, then slowly warmed up to room temperature and continued stirring for 12 hours. After completion of the reaction, tetrahydrofuran was removed by distillation under reduced pressure. The aqueous phase was washed with ethyl acetate (20 mL), followed by adjusting the pH with 10% aqueous citric acid (10 mL) to 1. The aqueous phase was extracted with ethyl acetate (200 mL x 2) and the organic phases were combined. The organic phase was washed sequentially with saturated saline (100 mL × 2) and dried over anhydrous sodium sulfate. After filtration, the solvent was evaporated under reduced pressure to give a white solid product (104 g, 90% yield).

24424-99-5 Synthesis

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

2177-63-1 Synthesis

2177-63-1
289 suppliers
$6.00/5g

7536-58-5
330 suppliers
$6.00/5g

Yield:7536-58-5 90%

Reaction Conditions:

with sodium hydrogencarbonate in tetrahydrofuran at 0 - 20; for 12.5 h;

Steps:

4.1 Boc-L-aspartic acid 4-benzyl ester
In the single-port in round bottomed flask add L - aspartic acid -4 - benzyl ester (79.7g, 357mmol), sodium bicarbonate (60g, 714.2mmol), water (700 ml) and tetrahydrofuran (550 ml). The reaction system is cooled to 0 °C, the reaction bottle adds by drops two carbon acid tert-butyl ester in (105g, 481mmol), the completion of the dropping, 0 °C reaction under half an hour later, slowly increased to room temperature, stirring for 12 hours. Reduced pressure to remove tetrahydrofuran, aqueous phase of ethyl acetate (20 ml) washing. The aqueous phase is 10% of the aqueous solution of citric acid (10 ml) to adjust the pH to 1, ethyl acetate (200 ml × 2) extraction, the combined organic phase, the organic phase with saturated salt water (100 ml × 2) washing, drying with anhydrous sodium sulfate. Filtering, evaporating the solvent under reduced pressure, to obtain white solid (104g, 90%).

References:

Guangdong Dongyangguang Pharmaceutical Co., Ltd.;Dongguan Dongyangguang Pharmaceutical Research And Development Co., Ltd.;Zhou Pingjian;Yang Chuanwen;Lin Jihua;Wang Xiaojun;Lao Jinhua;Xue Yaping;Cao Shengtian;Wu Fangyuan;Zhang Yingjun CN106866502, 2017, A Location in patent:Paragraph 0230-0234

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