Lithium Hydroxide → 4-(2-trimethylsilanyl-ethoxymethyl)-4H-thieno[3,2-b]pyrrole-5-carboxylic acid

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Reaction Conditions

Reaction Steps

Methyl 4-(2-trimethylsilanyl-ethoxymethyl)-4H-thieno[3,2-b]pyrrole-5-carboxylate (2.89 g, 9.27 mmol) was dissolved in 60 mL EtOH. A 2.0 M solution of LiOH (46 mL) was added and the reaction was heated to 75° C. for 30 min. EtOH was removed with a N2 stream. The residue was taken up in 300 mL water and acidified to pH 2 with conc. HCl, which gave a white precipitate. The precipitate was extracted into EtOAc. The solution was dried (Na2SO4), filtered and evaporated in vacuo to give 4-(2-trimethylsilanyl-ethoxymethyl)-4H-thieno[3,2-b]pyrrole-5-carboxylic acid (2.57 g, 93% yield). 1H NMR (400 MHz, (CD3)2CO) δ ppm −0.08 (s, 9H) 0.77-0.91 (m, 2H) 3.55 (t, 2H) 5.96 (s, 2H) 7.23 (d, J=5.37 Hz, 1H) 7.31 (s, 1H) 7.55 (d, J=5.37 Hz, 1H).

Provenance & Evidence