Acetic Acid → HCID 23529699, compound

Participants

Reaction Steps

A solution of 7.80 g of (R)-(1-benzyl-2,5-dioxo-pyrrolidin-3-yl)-carbamic acid benzyl ester (93% (R)-isomer) in 160 ml of acetic acid was treated with 0.78 g of 10% Pd/C (commercially available from Degussa; 1835) and hydrogenated at 30° C. for 20 min whereupon TLC and HPLC indicated completion of the reaction. The reaction mixture was filtered, evaporated and the residue crystallized from EtOAc and n-hexane to give 5.80 g (78%) of 3-(R)-amino-1-benzyl-pyrrolidin-2,5-dione acetic acid (1:2) as white crystals; HPLC (100%): HP 1050, nucleosil 100-5 C18 column, CH3CN, H2O, TFA system buffered with TBAHS; GC (99.8% as free amine): J and W, DB-1, 15 m×0.32 mm, carrier gas He, program: 50-320° C. (5° C./min); injector temp. 250° C.; FID: 320° C.; 91% (R)-isomer, analyzed as the corresponding trifluoroacetamide by GC (BGB-177): 15 m×0.25 mm, carrier gas: He; program: 150° C.-200° C. at 1° C./min; injector temp. 210° C.; FID: 220° C.; NMR (CDCl3, 400 MHz; 1.6 eq AcOH) 7.32 (m, 5H, H-ar), 5.64 (bs, 4H, NH), 4.65 (s, 2H, PhCH2O, 3.92 (dd, J=5.4 and 7.8, 1H, NCH), 3.05 (dd, J=7.8 and 18, COCH2, 1H), 2.50 (dd, J=18 and 5.4, COCH2, 1H), 2.08 (s,2×CH3CO2, 6H).

Provenance & Evidence