Triethylamine → Methyl (2S,4S)-1-[(3-cyanophenyl)sulfonyl]-4-hydroxypyrrolidine-2-carboxylate

Participants

Reaction Steps

To a solution of cis-4-hydroxy-L-proline methyl ester (10.0 g, 68.8 mmol), triethylamine (13.9 g, 138 mmol), and CH2Cl2 (200 mL) was added 3-cyanobenzene-1-sulfonyl chloride (13.9 g, 68.8 mmol). After 1 h, the reaction was partitioned between saturated aqueous NaHCO3 (75 mL) and CH2Cl2 (100 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3×75 mL). The combined organic layers were dried (MgSO4), filtered, and concentrated. The residue was purified on silica gel (1:99→30:70 ethyl acetate-hexanes) to afford the title compound as a colorless crystalline solid: 1H NMR (500 MHz, CDCl3) δ 8.19-8.18 (m, 1H), 8.13-8.11 (m, 1H), 7.89-7.85 (m, 1H), 7.69-7.65 (t, 1H), 4.52-4.50 (m, 1H), 4.44-4.43 (m, 1H), 3.67 (s, 3H), 3.52 (dd, 1H), 3.47-3.41 (m, 1H), 3.1 (d, 1H), 2.33-2.27 (m, 1H), 2.20-2.17 (m, 1H); LRMS (ESI) m/z 311 (311 calcd for C13H14N2O5S, M+H).

Provenance & Evidence