Pyridine → Ethyl 3-[bis(methylsulfonyl)amino]-6-chloro-2-(3-chlorobenzoyl)-1H-indole-1-carboxylate

Participants

Reaction Steps

To a solution of ethyl 3-amino-6-chloro-2-(3-chlorobenzoyl)-]-1H-indole-1-carboxylate (step 1 of Example 4, 507 mg, 1.25 mmol) in dichloromethane (15 ml) was added pyridine (0.32 ml, 4.04 mmol) and methanesulfonyl chloride (0.16 ml, 2.02 mmol). After stirring for 19 h, additional pyridine (1.3 ml, 16.2 mmol) and methanesulfonyl chloride (0.32 ml, 4.04 mmol) were added and the mixture heated at reflux for 17 h and then cooled to room temperature. The mixture was concentrated, and partitioned between ethyl acetate (200 ml) and 2 M aqueous HCl (100 ml). The organic layer was separated and washed with 2 M aqueous HCl (100 ml×2), saturated aqueous sodium bicarbonate (100 ml×3), and dried (Na2SO4). After removal of solvent the residue was purified by flash chromatography eluting with ethyl acetate/hexane (1:4) to afford the title compound (532 mg, 74%) as an oil.

Provenance & Evidence