[(3'S)-1'-[(tert-butoxy)carbonyl]-2-oxo-[1,3'-bipyrrolidin]-3-yl]triphenylphosphanium bromide → HCID 12993648, compound

Participants

Reaction Steps

4.2 (small scale): To a solution of 2.45 g of (1′-tert.-butoxycarbonyl-2-oxo-[1,3′]-bipyrrolidinyl-3-(R,S)-yl)-triphenyl-phosphonium bromide (preparation according EP 1 067 131 A1) in 6 ml of dichloromethane and 15 ml of toluene was added at −78° C. a solution of 432 mg of t-C4H9OK in 6 ml of THF over 10 min and stirring was continued at −78° C. for 10 min. The solution was treated at −78° C. with a solution of 3.50 g 7-[2-(5-amino-[1,2,4]thiadiazol-3-yl)-2-trityloxyimino-acetylamino]-3-formyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid benzhydryl ester in 6 ml of THF over 15 min and stirring was continued at −78° C. for 6 h and at −50° C. for 1 h after which time HPLC showed almost completion of the reaction. The reaction was quenched with a solution of 0.95 g of citric acid in 9 ml of water followed by addition of 12 ml of ethyl acetate, the organic layer was washed with NaHCO3 and brine, dried over MgSO4, filtered and the filtrate was evaporated. The residue was chromatographed on silica with ethyl acetate/hexane 10:1 to give 1.82 g of the title compound as a foam. IR (Nujol): 3450 m (NH2, NH), 1779 s, 1724 s, 1678 s, 1653 s (C═O). 1H-NMR (d6-DMSO): 9.93 (d, J=8.8, 1H, NH); 8.13 (s, br., 2H, NH2); 7.6-7.3 (m, 26H, H—ar., HC—C(3)); 6.96 (s, 1H, CH(Ph)2); 6.15 (dd, J=8.8 and 4.8, 1H, H—C(7)); 5.33 (d, J=4.8, 1H, H—C(6)); 4.59 (m, 1H, CH—N)); 3.91, 3.85 (d each, J=18 each, 2H, CH2—S(5)); 3,5-3,3 and 2.9 and 2.7 and 2.0 (m each, 6H and 1H and 1H and 2H, 5×CH2); 1.41 (s, 9H, (CH3)3C). MS (CI): 1044/100 (M+H+).

Provenance & Evidence