Trifluoroacetic acid → HCID 59605227, compound

Participants

Reaction Steps

Pyrrolidine (51 μL, 1.03 mmol) was added to a solution of (S)-pyrrolidine-1,3-dicarboxylic acid 1-tert-butyl ester (200 mg, 0.93 mmol), HATU (391 mg, 1.03 mmol) and DIPEA (410 μL, 2.35 mmol) in DMF and the resulting mixture stirred at ambient temperature for 1 h, then concentrated in vacuo. The resulting oil was partitioned between EtOAc and water. The organic layer was separated, washed with water and brine, then dried (MgSO4) and concentrated in vacuo to give (S)-3-(pyrrolidine-1-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester as a colourless oil. TFA (3 mL) was added to a solution of (S)-3-(pyrrolidine-1-carbonyl)pyrrolidine-1-carboxylic acid tert-butyl ester in DCM (10 mL) and the mixture stirred at ambient temperature for 1 h, then loaded onto an Isolute® SCX-2 cartridge (10 g). The cartridge was then washed with methanol and the desired product was subsequently eluted using 2 M NH3 in MeOH. The product was collected and concentrated in vacuo to afford the title compound as a pale brown oil (110 mg, 70%). 1H NMR (CDCl3, 400 MHz) δ 4.01 (m, 3H); 3.52-3.41 (m, 3H); 3.25-3.11 (m, 2H); 3.10-2.97 (m, 2H); 2.89 (dt, J=11.4, 7.5 Hz, 1H); 2.11-1.99 (m, 1H); 2.01-1.91 (m, 2H) and 1.93-1.82 (m, 2H).

Provenance & Evidence