Triethylamine → 2-(Thiophen-2-ylthio)succinic acid

Reaction equation

[C:1]([OH:8])(=[O:7])/[CH:2]=[CH:3]\[C:4]([OH:6])=[O:5].[S:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[SH:14].C(N(CC)CC)C>O1CCCC1>[S:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[S:14][CH:3]([CH2:2][C:1]([OH:8])=[O:7])[C:4]([OH:6])=[O:5]

Participants

Procedure

To a stirred solution of maleic acid (6.38 g, 0.055 mol) in tetrahydrofuran (50 ml) under nitrogen atmosphere was added 2-thiophenethiol (5.0 ml, 0.055 mol) and triethylamine (14.2 g, 0.14 mol). The mixture was stirred at gentle reflux for 16 hours overnight. The solvent was removed in vacuo and the residual oil was poured into 3NHCl (200 ml). The product was extracted into ethyl acetate (125 ml) in three portions, washed with saturated NaCl solution and dried over Na2SO4. The solution was filtered and concentrated in vacuo. This procedure gave the product as a light beige solid, 11.9 g, m.p. 136°-138.5° C. of 95% purity by HPLC. Yield was 93%.