Lithium Hydroxide → [(S)-7-Cyano-4-((2R,3R)-3-hydroxy-pyrrolidin-2-ylmethyl)-1,2,3,4-tetrahydro-cyclopenta[b]indol-2-yl]-carbamic acid isopropyl ester hydrochloride

Participants

Reaction Steps

A solution of (2R,3R)-3-(2-chloro-acetoxy)-2-((S)-7-cyano-2-isopropoxycarbonylamino-2,3-dihydro-1H-cyclopenta[b]indol-4-ylmethyl)-pyrrolidine-1-carboxylic acid tert-butyl ester (500 mg, 894.4 μmol) in MeOH (2 mL) is treated with 2 N LiOH solution (2 mL) and the suspension is stirred for 4 h at room temperature. The suspension is diluted with ethyl acetate (60 mL) and washed with water and brine. The organic portion is dried over sodium sulfate, filtered, and concentrated. The residue (0.39 g) is dissolved in 10 mL of MeOH (10 mL) and treated with 4 N HCl in 1,4-dioxane solution (10 mL). The solution is stirred for 2 h and concentrated in vacuo to afford 0.37 g (92%) of the title compound. LC-ES/MS m/z 383.2 [M+H]+, TR=1.86 min.

Provenance & Evidence