Water → diethyl 1-[3-[(tert-butoxycarbonyl)amino]butan-2-yl]-1H-indole-2,6-dicarboxylate

Participants

Reaction Steps

To a stirred suspension of 60% NaH dispersion in mineral oil (596 mg, 14.9 mmol) in DMF (14 mL) at 0° C. is added a solution of diethyl 1H-indole-2,6-dicarboxylate (Intermediate A, 3.9 g, 14.9 mmol) in DMF (14 mL). The mixture is stirred for 40 min, then a solution of tert-butyl 4,5-dimethyl-1,2,3-oxathiazolidine-3-carboxylate 2,2-dioxide (3.8 g, 14.9 mmol) in DMF (7 mL) is added. The reaction mixture is stirred for 30 min at 0° C. and then is warmed to room temperature and stirred for 65 h. Water is added and the mixture is stirred for 15 min before EtOAc (50 mL) is added. Then the organic layer is separated, washed with aqueous NH4Cl solution, water, and brine, dried (MgSO4) and concentrated to afford the crude title compound, which was used directly in the next reaction.

Provenance & Evidence