4H-Thieno[2,3-c]pyrrole-2-carboxylic acid, 5,6-dihydro-, methyl ester synthesis

Yield: 80%

Reaction Conditions:

with caesium carbonate;thiophenol in acetonitrile at 20; for 4 h;

Steps:

101.3
To a mixture of methyl 5-[(2-nitrophenyl)sulfonyl]-5,6-dihydro-4H-thieno[2,3-c]pyrrole-2- carboxylate (3.297 g, 8.95 mmol) and cesium carbonate (5.6 g, 17 mmol) in acetonitrile (95 mL) was added a solution of benzenethiol (1.8 mL, 17 mmol) in acetonitrile (20 mL). The resulting reaction mixture was stirred at room temperature for 4 hours. The solvent was removed in vacuo and the residue was washed exhaustively with Et₂O to afford an off white solid (3.326 g, 80 %). LCMS (FA) ES+ 184; ¹H NMR (400 MHz, MeOD) δ 7.59 (s, IH), 4.32 (t, J= 2.0 Hz, 2H), 4.17 (t, J= 2.0 Hz, 2H), 3.85 (s, 3H).

References:

MILLENNIUM PHARMACEUTICALS, INC.;BLACKBURN, Christopher;GIGSTAD, Kenneth, M.;XU, He WO2010/151317, 2010, A1 Location in patent:Page/Page column 137; 138