Ethanesulfonylchloride, 2-chloro- → ethenesulfonic acid [4-(3-cyano-1-ethyl-6-methoxy-1H-indol-2-yl)-phenyl]amide

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Reaction Steps

A solution of 2-(4-aminophenyl)-1-ethyl-6-methoxy-1H-indole-3-carbonitrile, prepared by example 1Ga step B, (0.82 mg, 2.82 mmol), in pyridine (10 mL) is treated dropwise with chloroethyl sulfonylchloride (0.38 mL, 3.66 mmol) at room temperature. After stirring for 4 h, the reaction mixture is quenched with ice-water and enough 6N HCl is added until the pH is lowered to 2. The suspension is extracted with hot EtOAc (3×). The organic phases are then washed sequentially with 1N HCl, H2O and saturated NaCl and dried and concentrated to give ethenesulfonic acid [4-(3-cyano-1-ethyl-6-methoxy-1H-indol-2-yl)-phenyl]amide as a pale orange solid which is used directly in the next step without further purification.

Provenance & Evidence