Methanol → (r)-(6-Cyano-2,3,4,9-tetrahydro-1h-carbazol-3-yl)-carbamic acid benzyl ester

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Reaction Steps

Resolve racemic (6-cyano-2,3,4,9-tetrahydro-1H-carbazol-3-yl)-carbamic acid benzyl ester (Preparation 61) (43.28 g) using preparative HPLC under the following conditions: Chiralcel OD column (8×35 cm), MeOH/0.2% dimethylethyl amine (DMEA) mobile phase at 350 ml/min flow rate with UV detection at 240 nM. Use 20 mL (666 mg) injections in 1:3 CHCl3/MeOH diluent with a runtime of 18.2 min and a stacked recycle injection (2 passes through the column to completely remove both isomers). First isomer to elute is is S isomer (21.34 g) with 98.2% ee. Second isomer to elute is R isomer (20.45 g) with 95.0% ee to give the title compound.

Provenance & Evidence