Thiophenol → HCID 20773303, compound

Participants

Reaction Steps

To a stirred solution of (R)-[(2S)-2-methyl-4-(2-nitrobenzenesulphonyl)-1-(3,3,3-trifluoro-2-hydroxy-2-methylpropionyl)piperazine] (Example 26; 19.71 g) in anhydrous DMF (60 ml) was added thiophenol (5.5 ml) followed by anhydrous potassium carbonate (18.7 g). The reaction mixture was allowed to stir at ambient temperature under argon for 4 hours, filtered and washed with DCM (2×300 ml). The filtrate was acidified with HCl (2 M, 250 ml) and the organic phase was separated and discarded. The aqueous phase was adjusted to pH 8 with 2 M NaOH and extracted into EtOAc (5×300 ml). The organic layers were combined, dried and concentrated to give a pale yellow gum which slowly crystallized (4.88 g). NMR (DMSO-d6, 100° C.): 1.21 (d, 3H), 1.54 (s, 3H), 2.49-2.55 (m, 1H), 2.65-2.75 (m, 3H), 2.82-2.91 (m, 2H), 2.97-3.01 (m, 1H), 4.31 (d, 1H), 4.60 (s, 1H); m/z (+ve ESP): 241 (M+H)+.

Provenance & Evidence