Hydrochloric Acid → 5-(Pyridine-2-sulfanyl)-thiazolidine-2,4-dione

Participants

Reaction Steps

To a solution of 5-bromo-thiazolidine-2,4-dione (28.24 g, 0.144 mol) and 2-mercaptopyridine [(II), 16.0 g, 0.144 mol] in dry THF (200 mL) at -78° C. was added lithium bis(trimethylsilyl)amide (1.0M in hexanes, 317 mL, 0.317 mol) dropwise over a 40 min period. After 30 min. the reaction mixture was warmed to room temperature. After an additional 3 hr, 10% HCl was added to pH=1. The layers were separated and the aqueous phase was extracted with ethyl acetate (2×500 mL). The combined organic phase was washed with water (500 mL), brine (500 mL), dried (MgSO4) and concentrated to provide the title compound as a green solid (30.45 g, 93%): mp 118°-120° C.; NMR (DMSO, d 6): δ12.35 (s, 1H, NH), 8.39 (d, J=5.3 Hz, 1H, PyrH), 7.69 (dd, J=7.3, 8.3 Hz, 1H, PryH), 7.42 (d, J=8.3 Hz, 1H, PyrH), 7.19 (dd, J=5.3,7.3 Hz, 1H, PyrH), 6.31 (s, 1H, CH), MS(EI): 226 (MI, 12%), 155 (10%), 79 (100%); Anal. (C8H6N2O2S2): C, H, N.

Provenance & Evidence