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ChemicalBook CAS DataBase List Boc-(R)-3-Amino-4-(2,4,5-trifluorophenyl)butanoic acid
486460-00-8

Boc-(R)-3-Amino-4-(2,4,5-trifluorophenyl)butanoic acid synthesis

9synthesis methods
(R)-β-tert-butoxycarbonylamino-2,4,5-trifluorophenylbutyric acid ethyl ester could used as a starting material and followed by adding Methanol and LiOHH2O as reaction reagents. Adding dichloromethane to the concentrate and adjust the pH to 2 with 2N HCl. Boc-(R)-3-Amino-4-(2,4,5-trifluorophenyl)butanoic acid could be obtained through further purification.BOC-(R)-3-AMINO-4-(2,4,5-TRIFLUORO-PHENYL)-BUTYRIC ACID
1048703-14-5 Synthesis
Carbamic acid, N-[(1R)-3-hydroxy-1-[(2,4,5-trifluorophenyl)methyl]propyl]-, 1,1-dimethylethyl ester

1048703-14-5
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Yield:486460-00-8 98%

Reaction Conditions:

with sodium hypochlorite;sodium chlorite;disodium hydrogenphosphate;sodium dihydrogenphosphate;2,2,6,6-Tetramethyl-1-piperidinyloxy free radical in water;acetonitrile at 38; for 0.333333 h;Solvent;

Steps:

2

In a 30 L dry reaction kettle, 2.5 kg of water, 86 g of disodium hydrogen phosphate and 37.5 g of sodium dihydrogen phosphate were added, it was stirred until solids were dissolved, 1.8L of acetonitrile, compound 6 (350g), TEMPO (12g)was added, the temperature was raised to about 38° C, an aqueous solution of sodium chlorite (250 g of sodium chlorite, 1 kg of water) and an aqueous solution (75 ml) of sodium hypochlorite (20 ml) were added in portions, added in ten portions, and added in batches every 20 min. The HPLC was followed until the reaction was complete, the control temperature was 10°C or less, an aqueous solution of saturated sodium sulfite was added dropwise, the external temperature was 50°C, the internal temperature was 40-45°C, and acetonitrile was distilled under reduced pressure, the temperature of the reaction solution was reduced to about 15 °C, ethyl acetate 350ml, 3N hydrochloric acid 1.3kg were added to adjust pH 3-4, the reaction solution was added with 2.5 L of water, and the temperature was stirred at 15-20 °C for 30 min, filtered, and the filter cake was washed twice with water, 1.5 L each time, the filter cake was blow dried 65 ° C to give compound 2 (361 g), as a white powder, yield 98%, see FIG 3,4,5

References:

CN107540575,2018,A Location in patent:Paragraph 0070-0071; 0074; 0084

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