Thiophenol → Bis(phenylsulfanyl)maleimide

Reaction equation

Br[C:2]1[C:7](=[O:8])[NH:6][C:4](=[O:5])[C:3]=1Br.C(=O)([O-])O.[Na+].[C:15]1([SH:21])[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>CO>[C:15]1([S:21][C:3]2[C:4](=[O:5])[NH:6][C:7](=[O:8])[C:2]=2[S:21][C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1

Participants

Procedure

To dibromomaleimide (80.0 mg, 0.3 mmol) and sodium hydrogencarbonate (130.2 mg, 1.6 mmol) in methanol (6 ml) was slowly added benzenethiol (66.6 μl, 0.7 mmol) in methanol (1 ml). The reaction was stirred for 15 min at RT. The solvent was removed in vacuo and the residual material was purified by flash chromatography on silica gel (petroleum ether: ethyl acetate, gradient elution from 9:1 to 7:3) to afford the desired product as bright yellow crystals (73 mg, 75%). λmax (50 mM sodium phosphate, pH 6.2, 40% MeCN, 2.5% DMF)/412 nm (ε/dm3 mol−1 cm−1 2245); 1H NMR (500 MHz, MeOD): δ=7.27-7.22 (m, 6H, Ar—H), 7.16-7.14 (m, 4H, Ar—H); 13C NMR (125 MHz, MeOD): δ=169.3 (C), 137.6 (C), 135.4 (C), 132.4 (CH), 130.1 (CH), 129.1 (CH); IR (solid, cm−1): 3285 (m), 3059 (w), 2924 (w), 1774 (m), 1715 (s); MS (CI) m/z, (%): 314 (M+H, 100), 206 (13), 111 (12); Mass calc. for C16H11O2NS2[H]: 314.0231. Found: 314.0309; m.p. 102-104° C. (Literature: 123-126° C.).