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ChemicalBook CAS DataBase List 3-PYRROLIDINEACETIC ACID, 1-[(1,1-DIMETHYLETHOXY)CARBONYL]-, ETHYL ESTER
664364-29-8

3-PYRROLIDINEACETIC ACID, 1-[(1,1-DIMETHYLETHOXY)CARBONYL]-, ETHYL ESTER synthesis

4synthesis methods
-

Yield:664364-29-8 86%

Reaction Conditions:

Stage #1: diethoxyphosphoryl-acetic acid ethyl esterwith sodium hydride in N,N-dimethyl-formamide at 0 - 20; for 0.5 h;
Stage #2: 3-oxo-pyrrolidine-1-carboxylic acid tert-butyl ester in N,N-dimethyl-formamide at 0 - 20; for 1 h;
Stage #3: with palladium 10% on activated carbon;hydrogen in ethanol;water at 20; for 2 h;

Steps:

21 5.1.21 tert-Butyl 3-(2-ethoxy-2-oxoethyl)pyrrolidine-1-carboxylate (25)

To a suspension of sodium hydride (60%, 420mg, 10.5mmol) in DMF (15mL) was added dropwise a solution of ethyl (diethoxyphosphoryl)acetate (2470mg, 11.0mmol) in DMF (5mL) at 0°C, and the mixture was stirred at room temperature for 0.5h. To the reaction mixture was added dropwise a solution of tert-butyl 3-oxopyrrolidine-1-carboxylate (24, 1850mg, 10.0mmol) in DMF (5mL) at 0°C, and the mixture was stirred at room temperature for 1h. To the reaction mixture was added 1M aqueous ammonium chloride solution at 0°C, and the mixture was partitioned between ethyl acetate and water. The organic layer was washed with saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure to give an orange oil. To a solution of the oil obtained above in ethanol (30mL) was added 10% palladium on carbon (wet, contains 50% water, 255mg), followed by stirring under a hydrogen atmosphere at room temperature for 2h. Insoluble material was removed by filtration through Celite, and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography [n-hexane/ethyl acetate=2:1] to give 25 (2210mg, 86%) as a colorless oil. 1H NMR-CDCl3 (400MHz) δ 1.26 (3H, t, J=9.6Hz), 1.46 (9H, s), 1.54 (1H, m), 2.06 (1H, m), 2.38 (2H, m), 2.56 (1H, m), 2.94 (1H, m), 3.29 (1H, m), 3.45 (1H, m), 3.60 (1H, m), 4.14 (2H, q, J=9.6Hz). FAB-MS: m/z 258 [M+H]+.

References:

Watanabe, Kazushi;Kakefuda, Akio;Yasuda, Minoru;Enjo, Kentaro;Kikuchi, Aya;Furutani, Takashi;Naritomi, Yoichi;Otsuka, Yukio;Okada, Minoru;Ohta, Mitsuaki [Bioorganic and Medicinal Chemistry,2013,vol. 21,# 17,p. 5261 - 5270]