1,1-Dimethylethyl (2S)-2-(aminocarbonyl)-1-pyrrolidinecarboxylate

White to off-white powder

General procedure: A mixture of compound 1 (1.00 g, 4.65 mmol), (Boc)A mixture of compound 8 (1.00 g, 4.65 mmol), (Boc)General procedure: The solution of Boc-L-proline 1 g, 4.6 mmol, ) in THF (12 mL) at 0 °C was charged with N-Methylmorpholine (0.54 g, 5.38 mmol). Then isobutyl chloroformate (0.75 g, 5.52 mmol) was added dropwise over 5 minutes. After 30 minutes of stirring the reaction was treated with the 25percent aqueous solution of ammonia (0.53 g, 15.18 mmol). The mixture was allowed to warm to room temperature and stirred for 4 h. Then, the mixture was concentrated under reduced pressure. Product was crystallized from hexane to yield 0.76 g (76percent) of product 1 as colorless crystals.71f[0529] (S)-tert-butyl 2-carbamoylpyrrolidine-1-carboxylate (71a): To a solution of 1-(tert- butoxycarbonyl)pyrrolidine-2-carboxylic acid (0.2 g, 0.93 mmol) in THE (13 mL), HOBT (142 mg, 0.93 mmol) was added followed by EDC (205 mg, 1.07 mmol). After stirring at r.t. for 6 hours, concentrated ammonium hydroxide (0.3 mL, 6.50 mmol) was added and the reaction mixture was stirred for 16-60 hours. Once reaction showed by TLC to be at completion, the organic solvent was removed under reduced pressure and the residue was diluted with ethyl acetate. The organic layer was washed with sodium bicarbonate solution and brine, dried over sodium sulfate, and concentrated to afford final product 71a (87 mg, 43percent) as an oil. 1H NMR (500 MHz, CDCI3) 64.17 (d, i=62.9 Hz, 1H), 3.35 (d, i=67.9 Hz, 2H), 2.26-1.98 (m, 2H), 1.92-1.75 (m, 2H), 1.39 (s, 9H); 13C NMR (126 MHz, CDCI3) 6175.15, 154.61, 80.33, 59.67, 47.15, 31.12, 28.37, 24.52. HRMS (ESI+): Calcd for C10H19N203 [M+H]: 215.1395, Eound:215.1389.

Molecular Weight:214.26
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:3
Exact Mass:214.13174244
Monoisotopic Mass:214.13174244
Topological Polar Surface Area:72.6
Heavy Atom Count:15
Complexity:270
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes